CVE-2021-4203: Race Condition
A use-after-free read flaw was found in sockgetsockopt() in net/core/sock.c due to SOPEERCRED and SOPEERGROUPS race with listen() (and connect()) in the Linux kernel. In this flaw, an attacker with a user privilege may lead to a system crash or a leak of internal kernel information.
In this, if the creds are replaced and freed at the wrong time, a use-after-free read occurs.
References:
https://lore.kernel.org/netdev/20210929225750.2548112-1-eric.dumazet@gmail.com/T/ https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=35306eb23814 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=1
Other sources
A use-after-free read flaw was found in sockgetsockopt() in net/core/sock.c due to SOPEERCRED and SOPEERGROUPS 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.
Affected Software
Remediation
Information
Patch Available
Patch Available
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2021-4203?
CVE-2021-4203 is rated as having a high severity level due to its potential to cause system crashes or leak internal kernel information.
How do I fix CVE-2021-4203?
To remediate CVE-2021-4203, upgrade to the recommended kernel versions as specified in security advisories or vendor documentation.
What type of vulnerability is CVE-2021-4203?
CVE-2021-4203 is a use-after-free read flaw in the Linux kernel that can be exploited due to improper handling of socket options.
Who is affected by CVE-2021-4203?
Users of vulnerable versions of the Linux kernel, specifically those using certain Red Hat and Debian kernels, are at risk from CVE-2021-4203.
What conditions are necessary for CVE-2021-4203 to be exploited?
An attacker must have user privileges on the system to exploit CVE-2021-4203, allowing them to trigger the vulnerability.