CVE-2024-2511

Unbounded memory growth with session handling in TLSv1.3

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.

Category

5.9
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 2.08% Top 20%
Vendor Advisory openssl.org
Affected: OpenSSL OpenSSL
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2024-2511?
CVE-2024-2511 has been scored as a medium severity vulnerability.
How to fix CVE-2024-2511?
To fix CVE-2024-2511, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2024-2511 being actively exploited in the wild?
It is possible that CVE-2024-2511 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2024-2511?
CVE-2024-2511 affects OpenSSL OpenSSL.
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