OpenBSD OpenSSH up to 6.5 Configuration child_set_env AcceptEnv access control

CVSS Meta Temp Score
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4.6$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in OpenBSD OpenSSH up to 6.5. Affected by this vulnerability is the function child_set_env of the component Configuration Handler. The manipulation of the argument AcceptEnv as part of Wildcard leads to access control. This vulnerability is listed as CVE-2014-2532. In addition, an exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in OpenBSD OpenSSH up to 6.5 (Connectivity Software). This issue affects the function child_set_env of the component Configuration Handler. The manipulation of the argument AcceptEnv as part of a Wildcard leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-264. Impacted is integrity. The summary by CVE is:

sshd in OpenSSH before 6.6 does not properly support wildcards on AcceptEnv lines in sshd_config, which allows remote attackers to bypass intended environment restrictions by using a substring located before a wildcard character.

The weakness was presented 03/21/2014 by Jann Horn as confirmed release notes (Website). It is possible to read the advisory at openssh.com. The identification of this vulnerability is CVE-2014-2532 since 03/17/2014. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details as well as a public exploit are known. The attack technique deployed by this issue is T1068 according to MITRE ATT&CK. The advisory points out:

OpenSSH prior to 6.6 could be tricked into accepting any enviornment variable that contains the characters before the wildcard character.

After immediately, there has been an exploit disclosed. The exploit is available at openssh.com. It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 73350 (Debian DSA-2894-1 : openssh - security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 185093 (HP-UX running HP Secure Shell Multiple Vulnerabilities (HPSBUX03188)).

Upgrading to version 6.6 eliminates this vulnerability.

The vulnerability is also documented in the databases at X-Force (91986), Tenable (73350), SecurityFocus (BID 66355†), Secunia (SA57488†) and Vulnerability Center (SBV-53102†). See VDB-12124, VDB-12724, VDB-82642 and VDB-92825 for similar entries. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 4.8

VulDB Base Score: 5.3
VulDB Temp Score: 4.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.9
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-264
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 73350
Nessus Name: Debian DSA-2894-1 : openssh - security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Port: 🔍

OpenVAS ID: 702894
OpenVAS Name: Debian Security Advisory DSA 2894-1 (openssh - security update
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Exploit Delay Time: 🔍

Upgrade: OpenSSH 6.6

Timelineinfo

03/17/2014 🔍
03/18/2014 +1 days 🔍
03/21/2014 +3 days 🔍
03/21/2014 +0 days 🔍
03/21/2014 +0 days 🔍
03/25/2014 +4 days 🔍
04/07/2014 +13 days 🔍
09/30/2015 +541 days 🔍
10/01/2015 +1 days 🔍
06/16/2021 +2085 days 🔍

Sourcesinfo

Vendor: openbsd.org

Advisory: openssh.com
Researcher: Jann Horn
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2014-2532 (🔍)
GCVE (CVE): GCVE-0-2014-2532
GCVE (VulDB): GCVE-100-12683

OVAL: 🔍

X-Force: 91986 - OpenSSH wildcard security bypass, Medium Risk
SecurityFocus: 66355 - OpenSSH 'child_set_env()' Function Security Bypass Vulnerability
Secunia: 57488 - OpenSSH "child_set_env()" Security Bypass Security Issue, Less Critical
SecurityTracker: 1029925
Vulnerability Center: 53102 - OpenSSH <6.6 Remote AcceptEnv Security Bypass via SSHD, Medium

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 03/25/2014 09:12
Updated: 06/16/2021 08:51
Changes: 03/25/2014 09:12 (97), 02/01/2018 11:48 (4), 06/16/2021 08:50 (3), 06/16/2021 08:51 (1)
Complete: 🔍
Cache ID: 216:8F3:103

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