Unbounded Memory Growth in QUIC Server Incoming Channel Queue
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- The rating the maker of the software gives it. Shown when it differs from the CVSS level.What do these mean? →
- Low (openssl)
- Fix
- Fixed in 4.0.2, 3.6.4, 3.5.8
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
Issue summary: When an OpenSSL QUIC server (Listener SSL object) processes valid QUIC Initial packets for unknown destination connection IDs, it can allocate and queue new incoming channels without enforcing any limit. Impact summary: A remote peer that can make many Initial packets reach the server listener faster than the application accepts connections, can cause the memory allocated to store the per-channel state to grow without any limits, potentially making the QUIC listener unavailable and causing Denial of Service. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: The function that handles inbound QUIC packets uses Connection-Id from the packet header to find an existing connection (QUIC channel). If no existing connection is found and the packet type is INITIAL, the function treats the packet as a new connection. It allocates a new channel object and inserts it into a queue where it waits to be accepted by the local application with SSL_accept(3ossl). The memory occupied by these initial channel objects may grow without bounds if the application is not able to call SSL_accept() frequently enough to serve these inbound connection requests. The issue is present since OpenSSL 3.5 when the QUIC server implementation was added. The fix introduces a limit for pending connections. The default limit is set to 256 pending connections (waiting to be accepted by the local application). Applications may change the default by calling SSL_set_value_uint(3ossl). FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- OpenSSL OpenSSL
From 4.0.0 · fixed in 4.0.2; From 3.6.0 · fixed in 3.6.4; From 3.5.0 · fixed in 3.5.8