Bug 1870171 (CVE-2020-16299)

Summary: CVE-2020-16299 ghostscript: division by zero in bj10v_print_page() in contrib/japanese/gdev10v.c could result in a DoS
Product: [Other] Security Response Reporter: Michael Kaplan <mkaplan>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: amasferr, chazlett, deekej, jlyle, mosvald, twaugh, zdohnal
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: ghostscript 9.51 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2021-05-18 20:35:08 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: 1870172, 1871262, 1871263    
Bug Blocks: 1870273    

Description Michael Kaplan 2020-08-19 13:23:54 UTC
A division by zero vulnerability in bj10v_print_page() in contrib/japanese/gdev10v.c of Artifex Software GhostScript v9.50 allows a remote attacker to cause a denial of service via a crafted PDF file. This is fixed in v9.51.

References:

https://bugs.ghostscript.com/show_bug.cgi?id=701801
https://git.ghostscript.com/?p=ghostpdl.git;a=commit;h=4fcbece46870

Comment 1 Michael Kaplan 2020-08-19 13:24:11 UTC
Created ghostscript tracking bugs for this issue:

Affects: fedora-all [bug 1870172]

Comment 4 Todd Cullum 2020-08-21 20:17:44 UTC
Flaw summary:

A division by zero could occur in /contrib/japanese/gdev10v.c at the line: count = ((out_end - (outl + 1)) / bytes_per_column) * bytes_per_column;

If bytes_per_column is 0 as designated by crafted yres input from a file manipulated by an attacker, this will cause a divide-by-zero exception and crash the program.

It is not immediately clear how the linked patch fixes this, as I do not see the patched function in the backtrace and the patched functionality is in a different file.

Comment 5 Todd Cullum 2020-08-21 20:19:03 UTC
Mitigation:

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Comment 6 errata-xmlrpc 2021-05-18 15:36:46 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1852 https://access.redhat.com/errata/RHSA-2021:1852

Comment 7 Product Security DevOps Team 2021-05-18 20:35:08 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2020-16299