VulnerabilityPublished 24 Jan 2024Updated 30 May 2025

CVE-2024-23644: trillium · HTTP Request/Response Splitting

Affects trilliumSource CVE Database V5

Not known to be exploited · CVSS 6.8 Medium · fixed in 0.3.12 : update trillium when convenient.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

6.8Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.3.12, 0.5.4

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Jan 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade trillium-rs/trillium-http to 0.3.12; trillium-rs/trillium-client to 0.5.4.

Affected software

Product	Affected	Fixed in
crates.iotrillium-rs/trillium-http`pkg:cargo/trillium-rs/trillium-http`Other threats	Affected <0.3.12	Fixed in 0.3.12
crates.iotrillium-rs/trillium-client`pkg:cargo/trillium-rs/trillium-client`Other threats	Affected <0.5.4	Fixed in 0.5.4

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should immediately upgrade trillium-http to version 0.3.12 or later and trillium-client to version 0.5.4 or later to benefit from the built-in validation and sanitization fixes. Until upgrades are applied, developers must implement strict input validation and sanitization on all untrusted data incorporated into HTTP headers, explicitly disallowing carriage return (\r), newline (\n), and null characters. Security teams should audit codebases for any direct or indirect usage of trillium-http and trillium-client libraries and review how header values and names are constructed and sourced. Employing Web Application Firewalls (WAFs) with rules to detect and block CRLF injection attempts can provide additional protection. Monitoring HTTP traffic for anomalies indicative of request/response splitting attacks is also recommended. Incorporating automated security testing, including fuzzing and static analysis focused on header injection, can help detect similar issues proactively. Finally, educating developers on secure handling of HTTP headers and the risks of CRLF injection is critical to prevent recurrence.

Description

Trillium is a composable toolkit for building internet applications with async rust. In `trillium-http` prior to 0.3.12 and `trillium-client` prior to 0.5.4, insufficient validation of outbound header values may lead to request splitting or response splitting attacks in scenarios where attackers have sufficient control over headers. This only affects use cases where attackers have control of request headers, and can insert "\r\n" sequences. Specifically, if untrusted and unvalidated input is inserted into header names or values. Outbound `trillium_http::HeaderValue` and `trillium_http::HeaderName` can be constructed infallibly and were not checked for illegal bytes when sending requests from the client or responses from the server. Thus, if an attacker has sufficient control over header values (or names) in a request or response that they could inject `\r\n` sequences, they could get the client and server out of sync, and then pivot to gain control over other parts of requests or responses. (i.e.exfiltrating data from other requests, SSRF, etc.) In `trillium-http` versions 0.3.12 and later, if a header name is invalid in server response headers, the specific header and any associated values are omitted from network transmission. Additionally, if a header value is invalid in server response headers, the individual header value is omitted from network transmission. Other headers values with the same header name will still be sent. In `trillium-client` versions 0.5.4 and later, if any header name or header value is invalid in the client request headers, awaiting the client Conn returns an `Error::MalformedHeader` prior to any network access. As a workaround, Trillium services and client applications should sanitize or validate untrusted input that is included in header values and header names. Carriage return, newline, and null characters are not allowed.

Impact

For European organizations using trillium-rs in their web applications or services, this vulnerability could lead to significant security risks. Exploitation could allow attackers to intercept or manipulate HTTP traffic, leading to data leakage, session hijacking, or unauthorized access to internal resources through SSRF. Confidentiality and integrity of communications could be compromised, especially in environments where trillium-rs is used to build APIs, microservices, or web servers. Given trillium-rs is a Rust-based toolkit, it may be popular among organizations adopting Rust for secure and performant web services. The impact is heightened in sectors handling sensitive data such as finance, healthcare, and government services prevalent in Europe. Additionally, the ability to pivot attacks via request/response splitting could facilitate lateral movement within networks, increasing the risk of broader compromise. Although no exploits are currently known, the medium severity rating and network attack vector suggest that attackers with some level of access or control over input headers could exploit this vulnerability remotely. This necessitates prompt attention to prevent potential data breaches or service disruptions.

Summary

CVE-2024-23644 is a vulnerability in the trillium-rs Rust toolkit, specifically in the trillium-http and trillium-client libraries prior to versions 0.3.12 and 0.5.4 respectively. The issue arises from improper validation of HTTP header names and values, allowing injection of CRLF (Carriage Return Line Feed) sequences. This improper neutralization of CRLF sequences (CWE-113) can lead to HTTP request/response splitting attacks. When an attacker can control header values or names and insert CRLF sequences, they can manipulate the HTTP protocol flow, causing the client and server to become desynchronized. This can enable various malicious activities such as request smuggling, response splitting, cross-site scripting (XSS), cache poisoning, and server-side request forgery (SSRF). The vulnerability affects scenarios where untrusted input is inserted into headers without proper sanitization. The flaw exists because trillium-http's HeaderName and HeaderValue types were constructed without checking for illegal bytes, allowing CRLF injection. In the fixed versions, invalid headers or values are omitted or cause errors before network transmission, preventing exploitation. The vulnerability has a CVSS 3.1 score of 6.8 (medium severity) with attack vector network, requiring low privileges but no user interaction, and impacts confidentiality and integrity but not availability. No known exploits are reported in the wild yet. The root cause is insufficient input validation and sanitization of HTTP headers in the affected trillium-rs versions, which is critical since HTTP headers are a fundamental part of web communication and security.

CWE-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') (opens in a new tab)
Variant weaknessOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers.
Implementation · Input Validation
Construct HTTP headers very carefully, avoiding the use of non-validated input data.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. If an input does not strictly conform to specifications, reject it or transform it into something that conforms.
Implementation · Output Encoding
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
HTTP Request Splitting (opens in a new tab)
Accessing/Intercepting/Modifying HTTP Cookies (opens in a new tab)
HTTP Response Splitting (opens in a new tab)
AJAX Footprinting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Jul 2025, 19:55 UTC

WeaknessesCWE-113

Technical details

References

Community reviews

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