CVE-2007-0844: The auth_via_key function in pam_ssh.c in pam_ssh before 1.92, when the allow_blank_passphrase option is disab

Routine

MEDIUM 6.4DOWNGRADE

CVE-2007-0844 is a medium-severity flaw (CVSS 6.4) affecting pam ssh. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The auth_via_key function in pam_ssh.c in pam_ssh before 1.92, when the allow_blank_passphrase option is disabled, allows remote attackers to bypass authentication restrictions and use private encryption keys requiring a blank passphrase by entering a non-blank passphrase.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.4 (Medium)
EPSS exploit chance	0.9% (top 41%)
CISA exploited list	No
Published	2007-02-08
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: pam ssh

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2007-02-08 17:28 UTCPublished CVE record published
2026-06-16 22:36 UTCUpdated Record last modified

pam ssh pam ssh DOWNGRADE

Affected: 1.91

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.91

1. Check installed version

apt-cache policy pam-ssh || rpm -q pam-ssh || pam-ssh --version

2. No fixed release: DOWNGRADE to a release before 1.91 (Debian / Ubuntu)

apt-cache madison pam-ssh sudo apt install pam-ssh=<VERSION_BEFORE_1.91> sudo apt-mark hold pam-ssh

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pam-ssh sudo dnf downgrade pam-ssh-<VERSION_BEFORE_1.91> sudo dnf versionlock add pam-ssh

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2007-0844?

pam ssh: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2007-0844 being exploited?

CVE-2007-0844 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2007-0844 affect?

CVE-2007-0844 affects pam ssh. Severity is medium (CVSS 6.4). The auth_via_key function in pam_ssh.c in pam_ssh before 1.92, when the allow_blank_passphrase option is disabled, allows remote attackers to bypass authentication restrictions and use private encryption keys requiring a blank passphrase by

How urgent is CVE-2007-0844?

Priority 37/100. No elevated risk signals yet.

Related CVEs

CVE-2009-1273 MEDIUM 5.0 DOWNGRADE pam_ssh 1.92 and possibly other versions, as used when PAM is compiled with USE=ssh, generates different error

References

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