Bug 1921916 (CVE-2021-3326) - CVE-2021-3326 glibc: Assertion failure in ISO-2022-JP-3 gconv module related to combining characters
Summary: CVE-2021-3326 glibc: Assertion failure in ISO-2022-JP-3 gconv module related ...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2021-3326
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1925091 1925093 1921917 1924919 1924920 1925088 1925089 1925090 1925092 1968676 1968677 1968678
Blocks: 1921918
TreeView+ depends on / blocked
 
Reported: 2021-01-28 20:47 UTC by Pedro Sampaio
Modified: 2023-09-23 18:23 UTC (History)
13 users (show)

Fixed In Version: glibc 2.33
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in glibc's iconv() functionality. This flaw allows an attacker capable of supplying a crafted sequence of characters to an application using iconv() to convert from ISO-2022-JP-3 to cause an assertion failure. The highest threat from this vulnerability is to system availability.
Clone Of:
Environment:
Last Closed: 2021-05-18 14:38:12 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2021:1585 0 None None None 2021-06-17 15:55:17 UTC

Description Pedro Sampaio 2021-01-28 20:47:06 UTC 
The iconv function in the GNU C Library (aka glibc or libc6) 2.32 and earlier, when processing invalid input sequences in the ISO-2022-JP-3 encoding, fails an assertion in the code path and aborts the program, potentially resulting in a denial of service.

Upstream bug:

https://sourceware.org/bugzilla/show_bug.cgi?id=27256

Upstream patch:

https://sourceware.org/git/?p=glibc.git;a=commit;h=7d88c6142c6efc160c0ee5e4f85cde382c072888
Comment 1 Pedro Sampaio 2021-01-28 20:47:39 UTC 
Created glibc tracking bugs for this issue:

Affects: fedora-all [bug 1921917]
Comment 4 Todd Cullum 2021-02-03 22:57:14 UTC 
Flaw technical summary:

glibc's iconv() function, when converting from ISO-2022-JP-3 ( which would have a conversion descriptor allocated by a call to e.g. `iconv_open ("UTF-8", "ISO-2022-JP-3")` ), can trigger an assertion failure in the form:

`../iconv/skeleton.c:746: gconv: Assertion `outbuf == outerr' failed.`

when processing a specific character sequence. Thus, any application which relies upon glibc's inconv() function and which uses the aforementioned encodings, could be susceptible to a denial of service if it processes the sequence, potentially provided by an attacker.
Comment 7 Todd Cullum 2021-02-03 23:55:17 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 10 Todd Cullum 2021-02-11 19:48:01 UTC 
Statement:

Exploitation of this flaw would cause the application to halt execution. It relies on processing untrusted input in the ISO-2022-JP-3 encoding or ISO-2022-JP-3 being used as a MIME charset in applications using iconv.
Comment 17 errata-xmlrpc 2021-05-18 13:26:26 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1585 https://access.redhat.com/errata/RHSA-2021:1585
Comment 18 Product Security DevOps Team 2021-05-18 14:38:12 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-2021-3326
Note You need to log in before you can comment on or make changes to this bug.