HOMEVULNERABILITIESCVE-2021-4203
MEDIUM

CVE-2021-4203

CWE-362Published: March 25, 2022· Updated: Jun 17, 2026

6.8
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2021-4203 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), availability disruption (denial of service), with a CVSS base score of 6.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityHigh
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected Vendors & Products

Linux1 product(s)
linux kernel
netapp19 product(s)
active iq unified managere-series santricity os controllerelement softwarehci management nodesolidfirebootstrap oshci compute nodea700s firmwarea700sh300s firmwareh300sh500s firmware+7
Oracle3 product(s)
communications cloud native core binding support functioncommunications cloud native core network exposure functioncommunications cloud native core policy
Source: NVD CPE · 24 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://bugs.chromium.org/p/project-zero/issues/detail?id=2230&can=7&q=modified-after%3Atoday-30&sort=-modified&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Modified%20Cve&cells=tiles&redir=1
PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=2036934
PATCHhttps://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=35306eb23814
PATCHhttps://www.oracle.com/security-alerts/cpujul2022.html
PATCHhttps://bugs.chromium.org/p/project-zero/issues/detail?id=2230&can=7&q=modified-after%3Atoday-30&sort=-modified&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Modified%20Cve&cells=tiles&redir=1
PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=2036934
PATCHhttps://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=35306eb23814
PATCHhttps://www.oracle.com/security-alerts/cpujul2022.html
ADVISORYhttps://security.netapp.com/advisory/ntap-20221111-0003/
ADVISORYhttps://security.netapp.com/advisory/ntap-20221111-0003/

All References (12)

→
https://bugs.chromium.org/p/project-zero/issues/detail?id=2230&can=7&q=modified-after%3Atoday-30&sort=-modified&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Modified%20Cve&cells=tiles&redir=1Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://bugzilla.redhat.com/show_bug.cgi?id=2036934Issue Tracking · Patch · Third Party Advisory
→
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=35306eb23814Patch · Vendor Advisory
→
https://lore.kernel.org/netdev/20210929225750.2548112-1-eric.dumazet%40gmail.com/T/
→
https://security.netapp.com/advisory/ntap-20221111-0003/Third Party Advisory
→
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch · Third Party Advisory
→
https://bugs.chromium.org/p/project-zero/issues/detail?id=2230&can=7&q=modified-after%3Atoday-30&sort=-modified&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Modified%20Cve&cells=tiles&redir=1Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://bugzilla.redhat.com/show_bug.cgi?id=2036934Issue Tracking · Patch · Third Party Advisory
→
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=35306eb23814Patch · Vendor Advisory
→
https://lore.kernel.org/netdev/20210929225750.2548112-1-eric.dumazet%40gmail.com/T/
→
https://security.netapp.com/advisory/ntap-20221111-0003/Third Party Advisory
→
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch · Third Party Advisory

Quick Facts

CVE IDCVE-2021-4203
CVSS Score6.8 / 10
SeverityMEDIUM
WeaknessCWE-362
CISA KEVNo
Affected3 vendor(s)
PublishedMar 25, 2022

Related CVEs (CWE-362)

CVE-2025-66419
10.0
CVE-2010-1228
10.0
CVE-2008-6598
10.0
CVE-2014-0703
10.0
CVE-2015-8556
10.0
CVE-2020-1660
9.9

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-4203 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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