CVE-2021-41991

Strongswan vulnerability

CVSS

7.5

EPSS

4.8%

EPSS pct

91th

Exploited

No known

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 vendor

Strongswan

Affected product

Strongswan

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness type (CWE)

CWE-190 — Integer Overflow or Wraparound

Published

2021-10-18

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring no privileges, no user interaction. Successful exploitation leads to high impact to availability.

Its EPSS score of 4.8% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 91% of all scored CVEs.

Check your external exposure to CVE-2021-41991

Confirm whether Strongswan Strongswan is running on any internet-facing host or subdomain.
Match discovered service fingerprints against the version affected by CVE-2021-41991.
Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2021-41991

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