curl vulnerabilities and threats

An `ftp://` transfer configured with `CURLUSESSL_NONE` can reuse a pooled FTP control connection that a previous easy handle upgraded with `STARTTLS` and authenticated using a client certificate. The second handle performs neither a new TLS handshake nor a new FTP login, so the server continues to authorize it under the first handle's certificate identity.

A flaw in the curl command line tool's logic makes it only set SSH host verification options when interacting directly using SFTP or SCP, and not as a result of following a redirect.

Setting `CURLOPT_AWS_SIGV4` to NULL but does not disable SigV4 authentication, contrary to expectations and documentation. A subsequent transfer on the same handle still sends an `Authorization: AWS4-HMAC-SHA256` header to whatever URL isset next, leaking state information.

During an upload, curl mishandles HTTP/2 `RST_STREAM` received from the server (with reason `HTTP_1_1_REQUIRED` or `REFUSED_STREAM`) leading to a use after free of a `struct Curl_easy` object.

CVE-2025-69135 is a high severity SQL Injection vulnerability in the Events Schedule - WordPress Events Calendar Plugin by CurlyThemes affecting versions up to and including 2.7.2. The flaw allows an attacker with subscriber-level privileges to inject SQL commands due to improper neutralization of special elements in SQL queries. This vulnerability can lead to high confidentiality impact and low availability impact but does not affect integrity. No official patch or remediation guidance is currently available from the vendor.

Version 3.0.7 of the Securly Chrome Extension downloads config.json over HTTP and compiles server-provided patterns as JavaScript regular expressions via new RegExp() without complexity validation. An on-path attacker can inject specific patterns to cause catastrophic backtracking, resulting in denial of service on all browsing.

Version 3.0.7 of the Securly Chrome Extension uses deprecated SHA-1 hashing for IWF CSAM URL matching (25,020 hashes) and CIPA blocklist matching (12,352 hashes).

Version 3.0.7 of the Securly Chrome Extension uses EVP_BytesToKey key derivation with MD5 and a single iteration for AES encryption. MD5 has been broken since 2004 and a single iteration provides no key stretching.

Version 3.0.7 of the Securly Chrome Extension dynamically registers content13.min.js as a content script via chrome.scripting.registerContentScripts() at runtime. This script is NOT declared in manifest.json and bypasses Chrome Web Store static security review. It runs on all URLs and immediately hides all page content, creates a full-page overlay, pauses all videos, and only restores content when the service worker confirms the page passes filtering. If Securly's servers are unreachable, pages remain indefinitely hidden.

Version 3.0.7 of the Securly Chrome Extension exposes multiple publicly accessible endpoints that allow unauthenticated access to sensitive data. The exposed information consists of SHA-1 hashes that are inadequately obfuscated using a simple Caesar cipher, which can be easily reversed to recover the original hash values and access the protected data.

Version 3.0.7 of the Securly Chrome Extension contains hardcoded, plaintext AES passphrases in securly.min.js. These keys decrypt crisis alert keyword data and intervention site data.

Version 3.0.7 of the Securly Chrome Extension downloads JSON files containing crisis alert keywords and filtering rules over unencrypted HTTP via the Fetch API. Other endpoints in the same extension correctly fetch IWF and CIPA data over HTTPS, demonstrating an inconsistent implementation of TLS.

Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the application to escape or exit this loop other than killing the thread/process. This might be used to DoS libcurl-using application.

libcurl supports *pinning* of the server certificate public key for HTTPS transfers. Due to an omission, this check is not performed when connecting with QUIC for HTTP/3, when the TLS backend is wolfSSL. Documentation says the option works with wolfSSL, failing to specify that it does not for QUIC and HTTP/3. Since pinning makes the transfer succeed if the pin is fine, users could unwittingly connect to an impostor server without noticing.

libcurl accidentally skips the certificate verification for QUIC connections when connecting to a host specified as an IP address in the URL. Therefore, it does not detect impostors or man-in-the-middle attacks.