CVE-2017-7562
First published: Fri Aug 25 2017(Updated: )
A flaw was found in krb5 certificate EKU validation which could lead to improper authorization if a forged certificate with the right EKU and no SAN is used. The PKINIT certauth eku module should never authoritatively authorize a certificate, because an extended key usage does not establish a relationship between the certificate and any specific user; it only establishes that the certificate was created for PKINIT client authentication. Upstream bug: <a href="https://github.com/krb5/krb5/pull/694">https://github.com/krb5/krb5/pull/694</a> Upstream patch: <a href="https://github.com/krb5/krb5/pull/694/commits/50fe4074f188c2d4da0c421e96553acea8378db2">https://github.com/krb5/krb5/pull/694/commits/50fe4074f188c2d4da0c421e96553acea8378db2</a> <a href="https://github.com/krb5/krb5/pull/694/commits/1de6ca2f2eb1fdbab51f1549a25a6903aefcc196">https://github.com/krb5/krb5/pull/694/commits/1de6ca2f2eb1fdbab51f1549a25a6903aefcc196</a> <a href="https://github.com/krb5/krb5/pull/694/commits/b7af544e50a4d8291524f590e20dd44430bf627d">https://github.com/krb5/krb5/pull/694/commits/b7af544e50a4d8291524f590e20dd44430bf627d</a>
Credit: secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Red Hat Enterprise Linux | =7.0 | |
| Red Hat Enterprise Linux Desktop | =7.0 | |
| Red Hat Enterprise Linux Server | =7.0 | |
| Red Hat Enterprise Linux Workstation | =7.0 | |
| Kerberos | >=1.0<1.16.1 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
- https://github.com/krb5/krb5/pull/694
- https://github.com/krb5/krb5/pull/694/commits/50fe4074f188c2d4da0c421e96553acea8378db2
- https://github.com/krb5/krb5/pull/694/commits/1de6ca2f2eb1fdbab51f1549a25a6903aefcc196
- https://github.com/krb5/krb5/pull/694/commits/b7af544e50a4d8291524f590e20dd44430bf627d
- https://access.redhat.com/errata/RHSA-2018:0666
- https://bugzilla.redhat.com/show_bug.cgi?id=1485510
- http://www.securityfocus.com/bid/100511
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7562
Frequently Asked Questions
What is the severity of CVE-2017-7562?
The severity of CVE-2017-7562 is classified as medium due to potential improper authorization issues.
How do I fix CVE-2017-7562?
To fix CVE-2017-7562, ensure you update to the latest version of krb5 that addresses this vulnerability.
What systems are affected by CVE-2017-7562?
CVE-2017-7562 primarily affects Red Hat Enterprise Linux 7.0 and MIT Kerberos 5 versions prior to 1.16.1.
What is the impact of CVE-2017-7562?
The impact of CVE-2017-7562 could lead to unauthorized access if a malicious user utilizes a forged certificate.
Is there a workaround for CVE-2017-7562?
Currently, no specific workarounds for CVE-2017-7562 are recommended other than applying security updates.
- agent/references
- agent/weakness
- agent/type
- agent/last-modified-date
- agent/remedy
- agent/first-publish-date
- collector/redhat-bugzilla
- source/Red Hat
- alias/CVE-2017-7562
- agent/trending
- agent/author
- agent/severity
- agent/description
- agent/event
- agent/source
- agent/softwarecombine
- agent/tags
- collector/nvd-index
- agent/software-canonical-lookup-request
- vendor/redhat
- canonical/red hat enterprise linux
- version/red hat enterprise linux/7.0
- canonical/red hat enterprise linux desktop
- version/red hat enterprise linux desktop/7.0
- canonical/red hat enterprise linux server
- version/red hat enterprise linux server/7.0
- canonical/red hat enterprise linux workstation
- version/red hat enterprise linux workstation/7.0
- vendor/mit
- canonical/kerberos
- version/kerberos/1.0