Alexandr Nedvedicky

**Name of the Vulnerable Software and Affected Versions** OpenSSL versions prior to 3.5.3-8.1 **Description** A double free issue exists in the QUIC server when processing an INITIAL packet. The default packet handler `port default packet handler()` creates a QRX (QUIC record layer RX) object for packet validation. If the subsequent channel creation via `port bind channel()` fails, the QRX object is freed. However, `port default packet handler()` also attempts to free the same QRX object upon detecting the failure, leading to heap corruption and a Denial of Service (DoS) through process termination. This condition can be triggered by sending a malformed INITIAL packet where the `DCID` (destination connection ID) is shorter than 8 bytes, causing `port bind channel()` to fail after `ossl quic lcidm enrol odcid()` detects the invalid length. **Recommendations** Update to version 3.5.3-8.1 or later.

**Name of the Vulnerable Software and Affected Versions** OpenSSL versions 3.5 and later **Description** An OpenSSL QUIC server can allocate and queue new incoming channels without enforcing a limit when processing valid QUIC Initial packets for unknown destination connection IDs. The system uses the `Connection-Id` from the packet header to locate an existing connection; if none is found and the packet type is INITIAL, a new channel object is allocated and queued to be accepted by the local application via the `SSL accept()` function. If the application cannot call `SSL accept()` frequently enough, the memory used for these channel objects can grow without bounds, potentially leading to a Denial of Service by making the QUIC listener unavailable. **Recommendations** Update OpenSSL to a version that implements a limit for pending connections. Applications can adjust the default limit of 256 pending connections by using the `SSL set value uint()` function.

**Name of the Vulnerable Software and Affected Versions** OpenSSL (affected versions not specified) **Description** A remote peer can cause unbounded memory allocation leading to a Denial of Service and abnormal termination of an application acting as a QUIC client or server. This occurs when a malicious peer floods the local QUIC stack with PATH CHALLENGE frames. The stack allocates a PATH RESPONSE frame for every received PATH CHALLENGE, but these frames are only freed once the remote peer acknowledges their reception, which a malicious actor will not do, resulting in heap memory exhaustion. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** versions not specified **Description** An uncommon configuration of clients performing DANE TLSA-based server authentication, when paired with uncommon server DANE TLSA records, may result in a use-after-free and/or double-free on the client side. A use after free can lead to data corruption, crashes, or arbitrary code execution. The issue affects clients that use TLSA records with both PKIX-TA(0/PKIX-EE(1)) and DANE-TA(2) certificate usages. Clients that treat PKIX TLSA records as unusable or support only PKIX usages are not vulnerable. The client must also communicate with a server publishing a TLSA RRset with both types of TLSA records. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.