Bug 1348626 (CVE-2015-8842)

Summary: CVE-2015-8842 systemd: improper use of tmpfiles.d to create persistent journal files
Product: [Other] Security Response Reporter: Cedric Buissart <cbuissar>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: johannbg, jrusnack, lnykryn, msekleta, muadda, ssahani, s, systemd-maint-list, systemd-maint, zbyszek
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Last Closed: 2016-06-21 16:04:18 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 1323985    

Description Cedric Buissart 2016-06-21 15:43:12 UTC
tmpfiles.d/systemd.conf in systemd before v230 does not explicitely set ACLs on persistent system.journal. This could allow improper permission set on the file.

seclist report:
http://seclists.org/oss-sec/2016/q2/34

Suse BTS:
https://bugzilla.suse.com/show_bug.cgi?id=972612

Fixed in commit:
https://github.com/systemd/systemd/commit/afae249efa4774c6676738ac5de6aeb4daf4889f

For additional information:
https://github.com/systemd/systemd/issues/1397

Comment 1 Cedric Buissart 2016-06-21 16:01:54 UTC
The persistent journal logging, the feature at fault, is disabled by default : Default journald storage is set to "auto". To run into the bug, the storage value needs to be changed to "persistent" to force journald to create the /var/log/journal folder on its own. 

In RHEL documentation, enabling persistent storage is suggested by simply creating the /var/log/journal directory, which does not trigger the bug :
 ⁠
20.10.5. Enabling Persistent Storage
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/s1-Using_the_Journal.html