CVE-2021-41991

HIGH
7.5
CVSS Score
Published: October 18, 2021 at 01:44 PM UTC
Updated: June 17, 2026 at 04:09 AM UTC
46 products affected across 4 vendorsDebian LinuxFedoraSINEMA Remote Connect Server

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Severity
HIGH7.5
Exploit prediction
EPSS 5%

Description

The in-memory certificate cache in strongSwan before 5.9.4 has a remote integer overflow upon receiving many requests with different certificates to fill the cache and later trigger the replacement of cache entries. The code attempts to select a less-often-used cache entry by means of a random number generator, but this is not done correctly. Remote code execution might be a slight possibility.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
siemens-cp-1543-1 (same device)
All versions
siemens-scalance-sc622-2c (same device)
All versions
siemens-scalance-sc632-2c (same device)
All versions
siemens-scalance-sc636-2c (same device)
All versions
siemens-scalance-sc642-2c (same device)
v < 2.3
Affected range stops below 2.3, so it looks safe — our inference, not a vendor statement
siemens-scalance-sc646-2c (same device)
All versions
siemens-simatic-cp-1242-7-gprs-v2 (same device)
All versions
siemens-simatic-cp-1243-1 (same device)

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-190

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