Vulnerability in OpenSSL
CVE-2024-2511
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.
EPSS: 0.540 (98.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Openssl — versions 3.2.0, 3.1.0, 3.0.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- openssl-security@openssl.org (vendor-advisory)
- openssl-security@openssl.org (patch)
- openssl-security@openssl.org (patch)
- openssl-security@openssl.org (patch)
- openssl-security@openssl.org (patch)
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
- 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
Frequently asked questions
- What is CVE-2024-2511?
- CVE-2024-2511 is a medium-severity vulnerability in OpenSSL, classified under CWE-1325. CVSS score: 5.9/10. Published 2024-04-08.
- How severe is CVE-2024-2511?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2024-2511 known to be exploited?
- 8 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.