CVE-2023-38325Public exploitNetwork attack vector

SSH certificate constraint bypass via single-layer parsing

Published Jul 14, 2023 · Updated Oct 30, 2024

Improper certificate validation in Python cryptography 40.0.0 through 41.0.1 allows remote attackers to bypass SSH certificate constraints. The _parse_exts_opts parser decodes a nonempty critical-option field only once, leaving its nested SSH-string length prefix in the returned value. Impact requires an application that trusts the parsed option values; affected parsing can misapply constraints such as force-command.

CVSS severity8.7
High
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in Python cryptography 40.0.0 through 41.0.1 allows remote attackers to bypass SSH certificate constraints. The _parse_exts_opts parser decodes a nonempty critical-option field only once, leaving its nested SSH-string length prefix in the returned value. Impact requires an application that trusts the parsed option values; affected parsing can misapply constraints such as force-command.

The record

CVE
CVE-2023-38325
Published
Jul 14, 2023
Updated
Oct 30, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-295
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 30, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.7GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
7.5OSVCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-295Improper Certificate Validation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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