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SSH CVE-2012-5975

CRITICAL
Improper Authentication (CWE-287)
2012-12-04 cve@mitre.org
9.3
CVSS 2.0 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication mechanism validation
MITRE ATT&CK

2 techniques across 2 tactics: Defense Evasion, Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 9.3 (CRITICAL). Attack characteristics: network attack vector, M complexity. Public proof-of-concept exploit code is available. EPSS exploitation probability: 25.75%.

Exploit ScenarioDerived

A remote attacker could bypass authentication mechanisms to gain unauthorized access by sending crafted requests to the affected application.

Emergency Immediate action required. Why: CRITICAL + active threat signals, no patch available.
No patch listed yet 25.7% exploitation probability (EPSS)

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AnalysisAI

The SSH USERAUTH CHANGE REQUEST feature in SSH Tectia Server 6.0.4 through 6.0.20, 6.1.0 through 6.1.12, 6.2.0 through 6.2.5, and 6.3.0 through 6.3.2 on UNIX and Linux, when old-style password. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable. Public exploit code available and EPSS exploitation probability 25.7%.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Implement multi-factor authentication, enforce strong password policies, use proven authentication frameworks.

Affects your stack

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Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Improper Authentication (CWE-287), which allows attackers to bypass authentication mechanisms to gain unauthorized access. The SSH USERAUTH CHANGE REQUEST feature in SSH Tectia Server 6.0.4 through 6.0.20, 6.1.0 through 6.1.12, 6.2.0 through 6.2.5, and 6.3.0 through 6.3.2 on UNIX and Linux, when old-style password authentication is enabled, allows remote attackers to bypass authentication via a crafted session involving entry of blank passwords, as demonstrated by a root login session from a modified OpenSSH client with an added input_userauth_passwd_changereq call in sshconnect2.c. Affected products include: Ssh Tectia Server. Version information: through 6.0.20.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 9.3 CRITICAL
AV:N/AC:M/Au:N/C:C/I:C/A:C

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
M
Confidentiality
C
Integrity
C
Availability
C

DescriptionCVE.org

The SSH USERAUTH CHANGE REQUEST feature in SSH Tectia Server 6.0.4 through 6.0.20, 6.1.0 through 6.1.12, 6.2.0 through 6.2.5, and 6.3.0 through 6.3.2 on UNIX and Linux, when old-style password authentication is enabled, allows remote attackers to bypass authentication via a crafted session involving entry of blank passwords, as demonstrated by a root login session from a modified OpenSSH client with an added input_userauth_passwd_changereq call in sshconnect2.c.

Threat Intelligence Overview

Threat Score
4.1/10
Composite threat intelligence
EPSS Score
25.7%
Top 4% exploitable
Exploit
POC
Public exploit code exists
Data Quality
6 sources
Confidence: High
NVD CVE.org EPSS POC (1) Exploit-DB GitHub Metasploit

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC Yes
EPSS 25.7%
Patch available No
Active threat Yes
Deciding rule
CRITICAL + active threat signals, no patch available
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Out-of-Cycle
Exploitation· derived
Active
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
High

Priority Score

107
Low Medium High Critical
KEV: 0
EPSS: +26
CVSS: +46
PoC: +20
Weaponized: +15
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

Affected Products (CPE)CVE.org

cpe:2.3:a:ssh:tectia_server:6.0.4:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.5:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.6:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.7:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.8:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.9:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.10:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.11:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.12:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.13:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.14:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.17:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.18:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.19:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.0.20.:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.1.0:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.1.1:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.1.2:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.1.3:*:*:*:*:*:*:*
cpe:2.3:a:ssh:tectia_server:6.1.4:*:*:*:*:*:*:*
+ 15 more

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