CVE-2021-22600
Double Free in net/packet/af_packet.c leading to priviledge escalation
- Published
- Updated
- Reserved
- Assigned by
Description
A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past ec6af094ea28f0f2dda1a6a33b14cd57e36a9755
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Linux Kernel Privilege Escalation Vulnerability.
- Added
- 11 Apr 2022
- Fix due (US federal)
- 2 May 2022
- Used by ransomware
- Not known
Apply updates per vendor instructions.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: it is being exploited.
Timeline
ID reserved
By Google
- 13 months later
· 13 months later
Published
- 3 months later
· 3 months later
Added to CISA KEV
Known exploited in the wild
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GoogleCNA (assigner) | 3.1 | Medium6.6 | CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:H |
| NVDNVD · Analyzed | 3.1 | High7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 6.6% · top 6.1% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.6.
Weakness
Affected products
- affected unspecified – < 5.4.168
- affected unspecified – < 5.10.88
- affected unspecified – < 5.15.11
- affected unspecified – < 5.16-rc6
References (5)
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=ec6af094ea28f0f2dda1a6a33b14cd57e36a9755 (opens in a new tab)x_transferred
- [debian-lts-announce] 20220309 [SECURITY] [DLA 2941-1] linux-4.19 security update (opens in a new tab)mailing-listx_transferred
- DSA-5096 (opens in a new tab)vendor-advisoryx_transferred
- https://security.netapp.com/advisory/ntap-20230110-0002/ (opens in a new tab)x_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22600 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-22600)Record last updated .