Bug 1448794 (CVE-2017-8804)

Summary: CVE-2017-8804 glibc: memory leak in sunrpc when decoding malformed XDR
Product: [Other] Security Response Reporter: Doran Moppert <dmoppert>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED WONTFIX QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: arjun, ashankar, codonell, dj, dominik.mierzejewski, fweimer, glibc-bugzilla, law, mfabian, mnewsome, pfrankli, sardella, siddhesh, slawomir
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2017-06-23 05:36:12 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1448796    
Bug Blocks: 1448130    

Description Doran Moppert 2017-05-08 07:58:09 UTC 
A crafted XDR message containing a string or bytes entity with a particularly large size but no content could cause xdr_opaque to leak virtual memory. Since the memory is never accessed, physical pages are not mapped (unless sysctl vm.overcommit_memory=2 is in effect). This was discovered in the wake of CVE-2017-8779.

Upstream issue:

https://sourceware.org/bugzilla/show_bug.cgi?id=21461

Upstream patch:

https://sourceware.org/ml/libc-alpha/2017-05/msg00105.html

CVE assignment:

https://seclists.org/oss-sec/2017/q2/218
Comment 1 Doran Moppert 2017-05-08 07:59:22 UTC 
Created glibc tracking bugs for this issue:

Affects: fedora-all [bug 1448796]
Comment 3 Doran Moppert 2018-08-06 23:54:16 UTC 
Per discussion on the libc-alpha mailing list (linked https://sourceware.org/bugzilla/show_bug.cgi?id=21461#c7), this is an application vulnerability rather than a flaw in glibc.  Users of the sunrpc library routines must be careful to use XDR_FREE, even when deserialisation failure occurs.