CVE-2020-10751

Published: 26 May 2020

A flaw was found in the Linux kernels SELinux LSM hook implementation before version 5.7, where it incorrectly assumed that an skb would only contain a single netlink message. The hook would incorrectly only validate the first netlink message in the skb and allow or deny the rest of the messages within the skb with the granted permission without further processing.

From the Ubuntu security team

Dmitry Vyukov discovered that the SELinux netlink security hook in the Linux kernel did not validate messages in some situations. A privileged attacker could use this to bypass SELinux netlink restrictions.

Priority

Negligible

CVSS 3 base score: 6.1

Status

Notes

SELinux specific, not the default LSM in Ubuntu.

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-10751
• https://git.kernel.org/linus/fb73974172ffaaf57a7c42f35424d9aece1a5af6
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10751
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fb73974172ffaaf57a7c42f35424d9aece1a5af6
• https://lore.kernel.org/selinux/CACT4Y+b8HiV6KFuAPysZD=5hmyO4QisgxCKi4DHU3CfMPSP=yg@mail.gmail.com/
• https://www.openwall.com/lists/oss-security/2020/04/30/5
• https://ubuntu.com/security/notices/USN-4391-1
• https://ubuntu.com/security/notices/USN-4389-1
• https://ubuntu.com/security/notices/USN-4390-1
• https://ubuntu.com/security/notices/USN-4412-1
• https://ubuntu.com/security/notices/USN-4413-1
• NVD
• Launchpad
• Debian

Bugs