CVE-2021-32606

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-05-11 · updated 2026-06-17
Weakness: CWE-416

Description

In the Linux kernel 5.11 through 5.12.2, isotp_setsockopt in net/can/isotp.c allows privilege escalation to root by leveraging a use-after-free. (This does not affect earlier versions that lack CAN ISOTP SF_BROADCAST support.)

Affected products

Fedoraproject Fedora: 32, 33, 34
Linux kernel: from 5.11 before 5.12.9 — fixed in 5.12.9

How to fix

Upgrade to a fixed version: Linux kernel 5.12.9. Check the vendor advisory for mitigations.

References

http://www.openwall.com/lists/oss-security/2021/05/12/1
http://www.openwall.com/lists/oss-security/2021/05/13/2
http://www.openwall.com/lists/oss-security/2021/05/14/1
http://www.openwall.com/lists/oss-security/2021/05/28/1
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2b17c400aeb44daf041627722581ade527bb3c1d
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/73D53S4IZFPFQMRABMXXLW4AJK3EULDX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GI7Z7UBWBGD3ABNIL2DC7RQDCGA4UVQW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HD3NJBG25AADVGPRC63RX2JOQBMPSWK4/
https://security.netapp.com/advisory/ntap-20210625-0001/
https://www.openwall.com/lists/oss-security/2021/05/11/16
http://www.openwall.com/lists/oss-security/2021/05/12/1
http://www.openwall.com/lists/oss-security/2021/05/13/2

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