CVE-2021-33033

Public Exploit

Description

The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd. This leads to writing an arbitrary value.

Category

7.8
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.02%
Vendor Advisory kernel.org Vendor Advisory kernel.org Vendor Advisory kernel.org Vendor Advisory kernel.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.7 mailing list patch vendor advisory
https://syzkaller.appspot.com/bug?id=96e7d345748d8814901c91cd92084ed04b46701e mailing list exploit third party advisory
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-cipso_v4_genopt third party advisory exploit
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ad5d07f4a9cd671233ae20983848874731102c08 mailing list patch vendor advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1165affd484889d4986cf3b724318935a0b120d8 mailing list patch vendor advisory
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.14 mailing list patch vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-33033?
CVE-2021-33033 has been scored as a high severity vulnerability.
How to fix CVE-2021-33033?
To fix CVE-2021-33033, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-33033 being actively exploited in the wild?
It is possible that CVE-2021-33033 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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