CVE-2022-32296 — The Linux kernel before 5
The Linux kernel before 5.17.9 allows TCP servers to identify clients by observing what source ports are used. This occurs because of use of Algorithm 4 ("Double-Hash Port Selection Algorithm") of RFC 6056.
Published
2022-06-05T22:15:08.797
Last modified
2026-10-14T17:17:40.420
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
01What is this vulnerability?
The Linux kernel before 5.17.9 allows TCP servers to identify clients by observing what source ports are used. This occurs because of use of Algorithm 4 ("Double-Hash Port Selection Algorithm") of RFC 6056.
02Affected products
No structured affected-product list available — see references below for vendor advisories.
03Active exploitation status
Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.
07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2022-06-05T22:15:08.797
- Last modified: 2026-10-14T17:17:40.420
09References
- arxiv.org — https://arxiv.org/abs/2209.12993
- cdn.kernel.org — https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.17.9
- git.kernel.org — https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4c2c8…
- github.com — https://github.com/0xkol/rfc6056-device-tracker
- lists.debian.org — https://lists.debian.org/debian-lts-announce/2022/07/msg00000.html
- www.debian.org — https://www.debian.org/security/2022/dsa-5173
- arxiv.org — https://arxiv.org/abs/2209.12993
- cdn.kernel.org — https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.17.9
- git.kernel.org — https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4c2c8…
- github.com — https://github.com/0xkol/rfc6056-device-tracker
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