CVE-2025-14821
Libssh: libssh: insecure default configuration leads to local man-in-the-middle attacks on windows
No known exploitation. EPSS puts it in the 2nd percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
A flaw was found in libssh. This vulnerability allows local man-in-the-middle attacks, security downgrades of SSH (Secure Shell) connections, and manipulation of trusted host information, posing a significant risk to the confidentiality, integrity, and availability of SSH communications via an insecure default configuration on Windows systems where the library automatically loads configuration files from the C:\etc directory, which can be created and modified by unprivileged local users.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.1% chance of exploitation activity in the next 30 days, which ranks it in the 2nd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
13 events over 146 days, from the signal feeds we watch.
- Patch availableworkaround available, record updated
- Patch availableworkaround available, record updated
- Patch availableworkaround available, record updated
- OpenVAS check added
- Publishedweakness classified, att&ck mapped
Affected products
And 5 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Scored 7.8 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- PersistenceT1574Hijack Execution Flowhigh confidence
Sources
References in the record
- access.redhat.com/security/cve/CVE-2025-14821&
- bugzilla.redhat.com/show_bug.cgi?id=2423148&
- redos.red-soft.ru/search/?iblock_id=24&q=CVE-2025-14821&
And 8 more references. See all after sign-in
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