What it is
CVE-2021-22600 is a vulnerability affecting Linux Kernel Kernel. 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...
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2021-22600
Kernel
Linux Kernel / Kernel · affected before 5.4.168
- Severity
- CVSS 6.6 · Medium
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 5.9%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.
Who is affected?
Linux Kernel / Kernel affected before 5.4.168.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Kernel
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
Vendor
Product
Affected
Status
Linux Kernel
Kernel
Before 5.4.168
Affected
Linux Kernel
Kernel
Before 5.10.88
Affected
Linux Kernel
Kernel
Before 5.15.11
Affected
Linux Kernel
Kernel
Before 5.16-rc6
Affected
- Published
- 26 Jan 2022
- Exploitation Reported
- 11 Apr 2022
- Attack vector
- Local
- Complexity
- High
- Privileges
- Low
- User interaction
- Required
Tags
cisa
linux
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2021-22600
- DSA-5096 debian.org · Vendor Advisory https://www.debian.org/security/2022/dsa-5096
- [debian-lts-announce] 20220309 [SECURITY] [DLA 2941-1] linux-4.19 security update lists.debian.org · Mailing List https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/... git.kernel.org · CVE Record https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/co...
- security.netapp.com/advisory/ntap-20230110-0002 security.netapp.com · CVE Record https://security.netapp.com/advisory/ntap-20230110-0002/
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CISA
Independent exploitation attestation added to the KEV Intelligence record.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2022-04-11 00:00 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
6.6
Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:H
EPSS
5.9%
Weaknesses
Timeline
From disclosure to observed exploitation
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2021-22600
Free JSON includes basic KEV fields{
"cve_id": "CVE-2021-22600",
"confidence": "Confirmed",
"cvss_score": 6.6,
"cvss_estimated": false,
"epss_score": 0.0587,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.