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Medium 5.9Published Apr 8, 2024

CVE-2024-2511Unbounded memory growth with session handling in TLSv1.3

Updated under an hour ago ()

Does this affect you?

It affects OpenSSL and 31 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
5.9 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-1325
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
openssl
NVD analysis
Deferred
Record last updated
Oct 15, 2026
First seen by InfoSec Signals
Oct 15, 2026

Affected products

Affected products
OpenSSL OpenSSL
openssl:openssl (from the name)
from 3.2.0 before 3.2.2; from 3.1.0 before 3.1.6; from 3.0.0 before 3.0.14; from 1.1.1 before 1.1.1y
CNA record
Siemens RUGGEDCOM RM1224 LTE(4G) EU
siemens:ruggedcom_rm1224_lte_4g_eu (from the name)
before V8.2
CISA ADP
Siemens RUGGEDCOM RM1224 LTE(4G) NAM
siemens:ruggedcom_rm1224_lte_4g_nam (from the name)
before V8.2
CISA ADP
Siemens RUGGEDCOM RST2428P
siemens:ruggedcom_rst2428p (from the name)
before V3.1
CISA ADP
Siemens SCALANCE M804PB
siemens:scalance_m804pb (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M812-1 ADSL-Router
siemens:scalance_m812_1_adsl_router (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M816-1 ADSL-Router
siemens:scalance_m816_1_adsl_router (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M826-2 SHDSL-Router
siemens:scalance_m826_2_shdsl_router (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M874-2
siemens:scalance_m874_2 (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M874-3
siemens:scalance_m874_3 (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M874-3 3G-Router (CN)
siemens:scalance_m874_3_3g_router_cn (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M876-3
siemens:scalance_m876_3 (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M876-3 (ROK)
siemens:scalance_m876_3_rok (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M876-4
siemens:scalance_m876_4 (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M876-4 (EU)
siemens:scalance_m876_4_eu (from the name)
before V8.2
CISA ADP
Siemens SCALANCE M876-4 (NAM)
siemens:scalance_m876_4_nam (from the name)
before V8.2
CISA ADP
Siemens SCALANCE MUM853-1 (A1)
siemens:scalance_mum853_1_a1 (from the name)
before V8.2
CISA ADP
Siemens SCALANCE MUM853-1 (B1)
siemens:scalance_mum853_1_b1 (from the name)
before V8.2
CISA ADP
Siemens SCALANCE MUM853-1 (EU)
siemens:scalance_mum853_1_eu (from the name)
before V8.2
CISA ADP
Siemens SCALANCE MUM856-1 (A1)
siemens:scalance_mum856_1_a1 (from the name)
before V8.2
CISA ADP
Siemens SCALANCE MUM856-1 (B1)
siemens:scalance_mum856_1_b1 (from the name)
before V8.2
CISA ADP
Siemens SCALANCE MUM856-1 (CN)
siemens:scalance_mum856_1_cn (from the name)
before V8.2
CISA ADP
Siemens SCALANCE MUM856-1 (EU)
siemens:scalance_mum856_1_eu (from the name)
before V8.2
CISA ADP
Siemens SCALANCE MUM856-1 (RoW)
siemens:scalance_mum856_1_row (from the name)
before V8.2
CISA ADP
Siemens SCALANCE S615 EEC LAN-Router
siemens:scalance_s615_eec_lan_router (from the name)
before V8.2
CISA ADP
Siemens SCALANCE S615 LAN-Router
siemens:scalance_s615_lan_router (from the name)
before V8.2
CISA ADP
Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family
siemens:scalance_xc_300_xr_300_xc_400_xr_500wg_xr_500_family (from the name)
all versions not affected
CISA ADP
Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family
siemens:scalance_xcm_xrm_xch_xrh_300_family (from the name)
before V3.1
CISA ADP
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)
from V3.1.0 before V3.1.5
CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)
from V3.1.0 before V3.1.5
CISA ADP
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name)
before V1.1.1
CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)
from V3.1.0 before V3.1.5
CISA ADP

References

  • vendor-advisory
  • patch
  • patch
  • patch
  • patch

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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