CVE-2022-33743 — network backend may cause Linux netfront to use freed SKBs While adding logic to

network backend may cause Linux netfront to use freed SKBs While adding logic to support XDP (eXpress Data Path), a code label was moved in a way allowing for SKBs having references (pointers) retained for further processing to nevertheless be freed.

01What is this vulnerability?

network backend may cause Linux netfront to use freed SKBs While adding logic to support XDP (eXpress Data Path), a code label was moved in a way allowing for SKBs having references (pointers) retained for further processing to nevertheless be freed.

02Affected products

Vendor	Product	Versions
Linux	Linux	consult Xen advisory XSA-405

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: 2022-07-05T12:50:19.000Z
• Last modified: 2024-08-03T08:09:22.607Z

09References

• xenbits.xenproject.org — https://xenbits.xenproject.org/xsa/advisory-405.txt
• xenbits.xen.org — http://xenbits.xen.org/xsa/advisory-405.html
• www.openwall.com — http://www.openwall.com/lists/oss-security/2022/07/05/5
• www.debian.org — https://www.debian.org/security/2022/dsa-5191