-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 OpenSSL Security Advisory [8th April 2024] ========================================== Unbounded memory growth with session handling in TLSv1.3 (CVE-2024-2511) ======================================================================== Severity: Low Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when processing TLSv1.3 sessions Impact summary: An attacker may exploit certain server configurations to trigger unbounded memory growth that would lead to a Denial of Service This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is being used (but not if early_data support is also configured and the default anti-replay protection is in use). In this case, under certain conditions, the session cache can get into an incorrect state and it will fail to flush properly as it fills. The session cache will continue to grow in an unbounded manner. A malicious client could deliberately create the scenario for this failure to force a Denial of Service. It may also happen by accident in normal operation. This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS clients. The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 1.0.2 is also not affected by this issue. OpenSSL 3.2, 3.1, 3.0, 1.1.1 are vulnerable to this issue. OpenSSL 3.2 users should upgrade to OpenSSL 3.2.2 once it is released. OpenSSL 3.1 users should upgrade to OpenSSL 3.1.6 once it is released. OpenSSL 3.0 users should upgrade to OpenSSL 3.0.14 once it is released. OpenSSL 1.1.1 users should upgrade to OpenSSL 1.1.1y once it is released (premium support customers only). Due to the low severity of this issue we are not issuing new releases of OpenSSL at this time. The fix will be included in the next releases when they become available. The fix is also available in commit e9d7083e (for 3.2), commit 7e4d731b (for 3.1) and commit b52867a9 (for 3.0) in the OpenSSL git repository. It is available to premium support customers in commit 5f8d2577 (for 1.1.1). This issue was reported on 27th February 2024 by Manish Patidar (Hewlett Packard Enterprise). The fix was developed by Matt Caswell. General Advisory Notes ====================== URL for this Security Advisory: https://www.openssl.org/news/secadv/20240408.txt Note: the online version of the advisory may be updated with additional details over time. For details of OpenSSL severity classifications please see: https://www.openssl.org/policies/secpolicy.html -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE3HAyZir4heL0fyQ/UnRmohynnm0FAmYT9+oACgkQUnRmohyn nm1jPRAAlvRaeTjSlW7PULpYxAfCrCfLlMzdC15ybP1mO12ixsbdBN4qRxcXWGFP TMqseW1pTCvcfQzEjSzswkio6kjBCh8iN3jSEPCJSIW7FWsZBpIZLwdqytp1pMaL D8Pe1B542dztrCQy+1pobHpxH8EbFVLX8X9VR0nbH2xx6a3cspGc+JwS7RRQzvK3 a27fW+KM/dyjRE8SGbFzxcgparZTcKDhB2WsjW4Hm0Z62J4v/mkxeC30SOrgH4j2 PBsjJW0XqxOdwM40aKqRPXfjnFwDWOaXVZDjARzT9+olnt01WJiXTpnuKKYQ9y1C 4rmUJo+qbxDnsTg+cjBiZGgsEGqH6Fu/VCw6cJF4Wj0+dZDpvludwTtLh4IRaeCp FqO6HWkdPg+qe9yKBvvqvf84i2kOvmSu4bVrJ5Zh524G3tYj43Uq76IiTSoLxM61 xmSVG3n0ri8H7aiavIjuq8U75uPhqmylwAIbL5wjEuIJayuprCINyBLAcV5VAprs avXD6D2XBXLFFDLZ4GEDuNIOWVxO3mGGxZ0kulpGWhESIGJaZk7Rvd+xr3jLtxwT dWdakCmOFtFIAcAdyYow4D5vCJr1p4iaLD3RCvle5bu3KIcThzWHo0ZnTygjyWt6 EgE0LExGT/1RTdtsXQaFQxzKd+gy4gdGfgl0u8ycYbMENKJ/tpE= =rMVW -----END PGP SIGNATURE-----
