Bug 1811684 (CVE-2020-10174)

Summary: CVE-2020-10174 timeshift: Arbitrary local code execution due to unsafe usage of temporary directory in /tmp/timeshift
Product: [Other] Security Response Reporter: Pedro Sampaio <psampaio>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED UPSTREAM QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: samuel.rakitnican
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Last Closed: 2020-03-09 16:31:59 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 1811685, 1811687    
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Description Pedro Sampaio 2020-03-09 14:36:42 UTC 
init_tmp in TeeJee.FileSystem.vala in Timeshift before 20.03 unsafely reuses a preexisting temporary directory in the predictable location /tmp/timeshift. It follows symlinks in this location or uses directories owned by unprivileged users. Because Timeshift also executes scripts under this location, an attacker can attempt to win a race condition to replace scripts created by Timeshift with attacker-controlled scripts. Upon success, an attacker-controlled script is executed with full root privileges. This logic is practically always triggered when Timeshift runs regardless of the command-line arguments used. 

References:

https://www.openwall.com/lists/oss-security/2020/03/06/3
https://github.com/teejee2008/timeshift/commit/335b3d5398079278b8f7094c77bfd148b315b462
https://github.com/teejee2008/timeshift/releases/tag/v20.03
Comment 1 Pedro Sampaio 2020-03-09 14:37:34 UTC 
Created timeshift tracking bugs for this issue:

Affects: epel-7 [bug 1811687]
Affects: fedora-all [bug 1811685]
Comment 2 Product Security DevOps Team 2020-03-09 16:31:59 UTC 
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.