CVE-2023-2283VulnerabilityPublished 26 May 2023Updated 3 Nov 2025

CVE-2023-2283: libssh · CWE-287

Affects libsshSource CVE Database V5

Not known to be exploited.

Data as of 25 Oct 2026, 22:43 UTC

Severity

Medium

Rated Medium by the CNA (redhat) · No CVSS score from NVD or the CNA

EPSS: 1.0% chance of exploitation in 30 days – higher than 64% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 May 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

The advisory notes that affected products are under investigation or may receive fixes in the near future. Users should monitor Red Hat advisories and update to fixed versions once available. In the meantime, consider applying any recommended mitigations from the vendor or restricting access to vulnerable libssh instances where feasible.

Description

CVE-2023-2283 is a vulnerability in libssh where the authentication check of a connecting client can be bypassed due to a flaw in the pki_verify_data_signature function related to memory allocation issues. This occurs when there is insufficient memory or limited memory usage, causing an error handling logic flaw that may return a success status incorrectly. The vulnerability is classified as improper authentication (CWE-287).

Impact

This vulnerability allows an attacker to bypass authentication checks in libssh, potentially enabling unauthorized access to services relying on libssh for secure connections. The impact is limited to low confidentiality and integrity impacts, with no availability impact reported. No known exploits are currently in the wild.

Summary

The vulnerability in libssh (CVE-2023-2283) arises from improper handling of the return value 'rc' in the pki_verify_data_signature function. Initially set to SSH_ERROR, 'rc' is overwritten with the result of pki_key_check_hash_compatible but not updated thereafter before cryptographic verification. If an error occurs between these steps, the function erroneously returns SSH_OK, effectively bypassing client authentication. This issue is triggered under conditions of insufficient memory or constrained memory usage.

CWE-287Improper Authentication (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Libraries or Frameworks
Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Fake the Source of Data (opens in a new tab)
Utilizing REST's Trust in the System Resource to Obtain Sensitive Data (opens in a new tab)
Session Hijacking (opens in a new tab)
Token Impersonation (opens in a new tab)
Upload a Web Shell to a Web Server (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 25 Oct 2026, 22:43 UTC

WeaknessesCWE-287

Technical details

References

Community reviews

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