Firejail: Administrator Compromise -- Existing Account

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             AUSCERT External Security Bulletin Redistribution

                               ESB-2021.3866
                    USN-5141-1: Firejail vulnerability
                             12 November 2021

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Firejail
Publisher:         Ubuntu
Operating System:  Ubuntu
Impact/Access:     Administrator Compromise -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2021-26910  

Reference:         ESB-2021.0516
                   ESB-2021.0463

Original Bulletin: 
   https://ubuntu.com/security/notices/USN-5141-1

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USN-5141-1: Firejail vulnerability
11 November 2021

Firejail could be made to overwrite files as the administrator.
Releases

  o Ubuntu 20.04 LTS

Packages

  o firejail - Application sandbox

Details

Roman Fiedler discovered that a race condition existed in Firejail
when using OverlayFS to prevent writes to the underlying file system. A
local attacker could use this to gain administrative privileges. Note:
this update disables support for OverlayFS in Firejail.

Update instructions

The problem can be corrected by updating your system to the following package
versions:

Ubuntu 20.04

  o firejail - 0.9.62-3ubuntu0.1

In general, a standard system update will make all the necessary changes.

References

  o CVE-2021-26910

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