CVE-2019-7639 — An issue was discovered in gsi-openssh-server 7

An issue was discovered in gsi-openssh-server 7.9p1 on Fedora 29. If PermitPAMUserChange is set to yes in the /etc/gsissh/sshd_config file, logins succeed with a valid username and an incorrect password, even though a failure entry is recorded in the /var/log/messages file.

01What is this vulnerability?

An issue was discovered in gsi-openssh-server 7.9p1 on Fedora 29. If PermitPAMUserChange is set to yes in the /etc/gsissh/sshd_config file, logins succeed with a valid username and an incorrect password, even though a failure entry is recorded in the /var/log/messages file.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-02-08T11:00:00.000Z
• Last modified: 2024-09-17T00:51:16.806Z

09References

• bugzilla.redhat.com — https://bugzilla.redhat.com/show_bug.cgi?id=1673802