Bug 1504045 (CVE-2017-15088) - CVE-2017-15088 krb5: Buffer overflow in get_matching_data()
Summary: CVE-2017-15088 krb5: Buffer overflow in get_matching_data()
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2017-15088
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: https://github.com/krb5/krb5/pull/707
Whiteboard:
Depends On: 1506622
Blocks: 1504046
TreeView+ depends on / blocked
 
Reported: 2017-10-19 11:44 UTC by Adam Mariš
Modified: 2021-02-17 01:20 UTC (History)
44 users (show)

Fixed In Version: krb5 1.16
Doc Type: If docs needed, set a value
Doc Text:
A stack based buffer overflow was found in the get_matching_data() function, when reading the principal's certificate during pkinit preauthentication. If the Certifcate Authority's subject line is sufficiently long, an attacker able to have a specially crafted certificate signed could crash the authentication process, such as kinit, or, possibly, run arbitrary code.
Clone Of:
Environment:
Last Closed: 2018-01-10 11:15:20 UTC
Embargoed:

Attachments (Terms of Use)

Description Adam Mariš 2017-10-19 11:44:38 UTC 
A buffer overflow vulnerability was found in get_matching_data() function when both the CA cert and the user cert have a long subject affecting krb5 that includes certauth plugin. Attack requires a validated certificate with a long subject and issuer, and a "pkinit_cert_match" string attribute on some principal in the database. A remote code execution exploit might also require that the attacker gets to choose the contents of the issuer in the validated cert.

Bug report:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=871698
Comment 5 Cedric Buissart 2017-10-26 13:07:57 UTC 
Created krb5 tracking bugs for this issue:

Affects: fedora-all [bug 1506622]
Comment 6 Adam Mariš 2017-10-31 12:03:06 UTC 
Upstream patch:

https://github.com/krb5/krb5/commit/fbb687db1088ddd894d975996e5f6a4252b9a2b4
Comment 9 Cedric Buissart 2018-01-10 11:14:16 UTC 
Statement:

This issue affects the versions of krb5 as shipped with Red Hat Enterprise Linux 7. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
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