OpenSSH up to 6.x on Non-OpenBSD sshd monitor.c MONITOR_REQ_PAM_INIT_CTX Request input validation

CVSS Meta Temp Score
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CTI Interest Score
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5.8$0-$5k0.00

Summaryinfo

A vulnerability was found in OpenSSH up to 6.x on Non-OpenBSD and classified as problematic. Affected by this vulnerability is an unknown functionality of the file monitor.c of the component sshd. Such manipulation as part of MONITOR_REQ_PAM_INIT_CTX Request leads to input validation. This vulnerability is documented as CVE-2015-6563. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenSSH up to 6.x on Non-OpenBSD (Connectivity Software) and classified as problematic. Affected by this issue is an unknown code of the file monitor.c of the component sshd. The manipulation as part of a MONITOR_REQ_PAM_INIT_CTX Request leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is confidentiality, integrity, and availability. CVE summarizes:

The monitor component in sshd in OpenSSH before 7.0 on non-OpenBSD platforms accepts extraneous username data in MONITOR_REQ_PAM_INIT_CTX requests, which allows local users to conduct impersonation attacks by leveraging any SSH login access in conjunction with control of the sshd uid to send a crafted MONITOR_REQ_PWNAM request, related to monitor.c and monitor_wrap.c.

The weakness was released 08/24/2015 by Moritz Jodeit as confirmed mailinglist post (oss-sec). The advisory is shared for download at seclists.org. This vulnerability is handled as CVE-2015-6563 since 08/21/2015. The attack needs to be approached locally. No form of authentication is required for exploitation. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 86656 (AIX OpenSSH Advisory : openssh_advisory6.asc), which helps to determine the existence of the flaw in a target environment. It is assigned to the family AIX Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 236003 (Red Hat Update for openssh (RHSA-2016:0741)).

Upgrading to version 7.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at X-Force (105881), Tenable (86656) and SecurityFocus (BID 76317†). Entries connected to this vulnerability are available at VDB-77397, VDB-77398, VDB-78828 and VDB-80656. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.1
VulDB Meta Temp Score: 5.8

VulDB Base Score: 5.9
VulDB Temp Score: 5.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

ADP CISA Base Score: 6.4
ADP CISA Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 86656
Nessus Name: AIX OpenSSH Advisory : openssh_advisory6.asc
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍

OpenVAS ID: 14611
OpenVAS Name: Amazon Linux Local Check: alas-2015-625
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍
Upgrade: OpenSSH 7.0
Patch: github.com

Timelineinfo

08/12/2015 🔍
08/21/2015 +9 days 🔍
08/23/2015 +2 days 🔍
08/24/2015 +1 days 🔍
08/24/2015 +0 days 🔍
05/28/2026 +3929 days 🔍

Sourcesinfo

Advisory: d4697fe9a28dab7255c60433e4dd23cf7fce8a8b
Researcher: Moritz Jodeit
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2015-6563 (🔍)
GCVE (CVE): GCVE-0-2015-6563
GCVE (VulDB): GCVE-100-77396

OVAL: 🔍

X-Force: 105881 - OpenSSH monitor component security bypass
SecurityFocus: 76317 - OpenSSH PAM Support Multiple Remote Code Execution Vulnerabilities

See also: 🔍

Entryinfo

Created: 08/24/2015 10:17
Updated: 05/28/2026 00:52
Changes: 08/24/2015 10:17 (52), 11/05/2017 00:47 (22), 06/13/2022 08:40 (4), 06/13/2022 08:44 (1), 06/13/2022 08:47 (1), 05/28/2026 00:52 (26)
Complete: 🔍
Cache ID: 216::103

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