CVE-2021-3493

Linux Kernel Privilege Escalation Vulnerability

Ubuntu Linux

The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.

17. Apr 2021

Ausgewertete Quellen

• Ubuntu
  https://ubuntu.com/security/notices/USN-4917-1
• Hinweis
  http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html
• Hinweis
  http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html
• Hinweis
  http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html
• Hinweis
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52
• Hinweis
  https://www.openwall.com/lists/oss-security/2021/04/16/1
• CISA
  https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-3493
• CISA
  Linux Kernel Privilege Escalation Vulnerability
• NVD
  CVE-2021-3493