CVE-2021-41991

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.

Summary:

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.

Reference Links(if available):

  • https://www.strongswan.org/blog/2021/10/18/strongswan-vulnerability-(cve-2021-41991).html
  • https://github.com/strongswan/strongswan/releases/tag/5.9.4
  • https://www.debian.org/security/2021/dsa-4989
  • https://lists.debian.org/debian-lts-announce/2021/10/msg00014.html
  • https://lists.fedoraproject.org/archives/list/[email protected]/message/WQSQ3BEC22NF4NCDZVCT4P3Q2ZIAJXGJ/
  • CVSS Score (if available)

    v2: / MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P

    v3: / HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

    Links to Exploits(if available)