Use After Free in Linux Kernel
CVE-2021-4203
A use-after-free read flaw was found in sock_getsockopt() in net/core/sock.c due to SO_PEERCRED and SO_PEERGROUPS race with listen() (and connect()) in the Linux kernel. In this flaw, an attacker with a user privileges may crash the system or leak internal kernel information.
Vulnerability class: Race Condition
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H.
EPSS exploit prediction
EPSS: 0.017 (77.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- bugs.chromium.org/p/project-zero/issues/detail (Exploit, Patch, Third Party Advisory, Issue Tracking)
- git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/ (Patch, Vendor Advisory)
- lore.kernel.org/netdev/20210929225750.2548112-1-eric.dumazet@gmail.com/T/
- www.oracle.com/security-alerts/cpujul2022.html (Patch, Third Party Advisory)
- security.netapp.com/advisory/ntap-20221111-0003/ (Third Party Advisory)
Frequently asked questions
- What is CVE-2021-4203?
- CVE-2021-4203 is a medium-severity vulnerability in Linux Kernel, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 6.8/10. Published 2022-03-25.
- How severe is CVE-2021-4203?
- Medium severity. CVSS v3 base score is 6.8 out of 10.
- Is CVE-2021-4203 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.