SB2020052714 - Security restrictions bypass in SELinux netlink
Published: May 27, 2020
Security Bulletin ID
SB2020052714
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2020-10751)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due in the Linux kernels SELinux LSM hook implementation where the kernel 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.
Remediation
Install update from vendor's website.
References
- 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