CVE-2024-2511: OpenSSL

Medium severity, CVSS 5.9. EPSS: 52.4% chance of exploitation in the next 30 days.

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.

Affected products

  • OpenSSL OpenSSL: from 3.2.0, before 3.2.2 (fixed in 3.2.2); from 3.1.0, before 3.1.6 (fixed in 3.1.6); from 3.0.0, before 3.0.14 (fixed in 3.0.14); from 1.1.1, before 1.1.1y (fixed in 1.1.1y)
  • Siemens Ruggedcom RM1224 LTE4G Eu: before V8.2 (fixed in V8.2)
  • Siemens Ruggedcom RM1224 LTE4G Nam: before V8.2 (fixed in V8.2)
  • Siemens Ruggedcom RST2428P: before V3.1 (fixed in V3.1)
  • Siemens Scalance m804pb: before V8.2 (fixed in V8.2)
  • Siemens Scalance m812-1 Adsl-Router: before V8.2 (fixed in V8.2)
  • Siemens Scalance m816-1 Adsl-Router: before V8.2 (fixed in V8.2)
  • Siemens Scalance m826-2 Shdsl-Router: before V8.2 (fixed in V8.2)
  • Siemens Scalance m874-2: before V8.2 (fixed in V8.2)
  • Siemens Scalance m874-3: before V8.2 (fixed in V8.2)
  • Siemens Scalance m874-3 3g-Router Cn: before V8.2 (fixed in V8.2)
  • Siemens Scalance m876-3: before V8.2 (fixed in V8.2)
  • Siemens Scalance m876-3 Rok: before V8.2 (fixed in V8.2)
  • Siemens Scalance m876-4: before V8.2 (fixed in V8.2)
  • Siemens Scalance m876-4 Eu: before V8.2 (fixed in V8.2)
  • Siemens Scalance m876-4 Nam: before V8.2 (fixed in V8.2)
  • Siemens Scalance MUM853-1 a1: before V8.2 (fixed in V8.2)
  • Siemens Scalance MUM853-1 b1: before V8.2 (fixed in V8.2)
  • Siemens Scalance MUM853-1 Eu: before V8.2 (fixed in V8.2)
  • Siemens Scalance MUM856-1 a1: before V8.2 (fixed in V8.2)
  • Siemens Scalance MUM856-1 b1: before V8.2 (fixed in V8.2)
  • Siemens Scalance MUM856-1 Cn: before V8.2 (fixed in V8.2)
  • Siemens Scalance MUM856-1 Eu: before V8.2 (fixed in V8.2)
  • Siemens Scalance MUM856-1 Row: before V8.2 (fixed in V8.2)
  • Siemens Scalance s615 Eec Lan-Router: before V8.2 (fixed in V8.2)
  • and 7 more

Published 2024-04-08. Last modified 2026-06-17.