CVE-2023-51385

In ssh in OpenSSH before 9.6, OS command injection might occur if a user name or host name has shell metacharacters, and this name is referenced by an expansion token in certain situations. For example, an untrusted Git repository can have a submodule with shell metacharacters in a user name or host name.

CVSS: 6.5Mediumscored by CISA
Exploited in the wild: Not knownUnvetted proof-of-concept code on GitHub; not in CISA KEV
EPSS: 19.8%chance of exploitation in the next 30 daystop 3% of scored CVEsFIRST score of 11 Nov 2026
Fix: Patch availablesee the advisories in the references
Published: 18 Dec 2023analysed here 12 Nov 2026

Summary

Triage

Attack surface: Server-side
Exploitable: At runtime
Attack vector: network
Weakness: CWE-78 OS Command Injection
Can a WAF block it?: Partly. See why

The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.

Affected products

Products named in our analysis

openbsd:openssh
debian:debian_linux

Fix and mitigation

WAF and other mitigations

Can a WAF block it? Partly. OS command injection puts shell syntax into the request. WAF rules catch common shell commands but miss encoded or unusual payloads.

Also consider: shlex/execve-style APIs

Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.

Remediation steps (AI-written)

Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.

Exploitation evidence

CISA KEV catalog: Not listed as of our last sync.
Public exploit code: Unvetted proof-of-concept code on GitHub: 23 GitHub proofs of concept
CISA SSVC: exploitation poc, automatable yes, technical impact totalAssessed by CISA 15 Aug 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.

GitHub proofs of concept

vin01/poc-proxycommand-vulnerable50 stars
LtmThink/CVE-2023-51385_test7 stars
Le1a/CVE-2023-513855 stars
WOOOOONG/CVE-2023-513852 stars

and 19 more repositories

Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.

Timeline

28 Sept 2023First proof-of-concept repository on GitHub (unvetted)
18 Dec 2023Published82 days (about 3 months) later
15 Aug 2025CISA SSVC assessment: exploitation poc606 days (about 2 years) later
15 Oct 2026CVE record last updated425 days (about 1 year) later
12 Nov 2026Analysed by vulneraibility.com29 days later

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Metric	Value	What it means
Attack vector	NetworkReachable over the internet or any routable network.	Reachable over the internet or any routable network.
Attack complexity	LowRepeatable attack, no special conditions.	Repeatable attack, no special conditions.
Privileges required	NoneThe attacker needs no prior access.	The attacker needs no prior access.
User interaction	NoneNo victim action needed.	No victim action needed.
Scope	UnchangedImpact stays within the vulnerable component.	Impact stays within the vulnerable component.
Confidentiality	LowPartial data disclosure.	Partial data disclosure.
Integrity	LowLimited modification possible.	Limited modification possible.
Availability	NoneThe service stays up.	The service stays up.

Common questions

Is CVE-2023-51385 being exploited?

Not confirmed. CVE-2023-51385 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 20% probability of exploitation in the next 30 days.

How severe is CVE-2023-51385?

CVE-2023-51385 is rated Medium with a CVSS score of 6.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2023-51385?

Yes. A fix has been recorded for CVE-2023-51385. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2023-51385 affect?

CVE-2023-51385 affects openbsd:openssh, debian:debian_linux. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

References

NVD CVE.org CVE Details Source

16 references in the CVE record, grouped by the tags the record gives them.

Advisories (2)

debian.org /security/2023/dsa-5586
security.gentoo.org /glsa/202312-17

Where the data on this page comes from

CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
NVD: CVSS and CPE data
CISA Vulnrichment (ADP): SSVC decision points
FIRST EPSS: exploit probability and percentile
PoC-in-GitHub: GitHub repositories that claim a proof of concept

Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.

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