CVE-2024-2511

CVE-2024-2511 is a medium-severity vulnerability with a CVSS 3.x base score of 5.9. Its EPSS exploit-prediction score of 54% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-1325.

Key facts

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2024-2511?
CVE-2024-2511 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-2511 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 54% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2024-2511?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-2511 have an EU (EUVD) identifier?
Yes. CVE-2024-2511 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-27460.
When was CVE-2024-2511 published?
CVE-2024-2511 was published on 2024-04-08 and last updated on 2026-06-17.

References

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