SB2016122003 - Multiple vulnerabilities in OpenSSH

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Main Vulnerability Database SB2016122003

SB2016122003 - Multiple vulnerabilities in OpenSSH

Published: December 20, 2016 Updated: December 21, 2016

Security Bulletin ID SB2016122003
Severity
Low
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 secuirty vulnerabilities.


1) Improper input validation (CVE-ID: N/A)

The vulnerability allows a remote attacker to bypass certain security restrictions.

The vulnerability exists due to an error in sshd, which can be used to bypass address-based access controls if the AllowUser directive is configured with invalid CIDR address ranges.

Successful exploitation of this vulnerability may allow a remote attacker to bypass implemented access control mechanisms and perform a further attacks against vulnerable system.


2) Buffer overflow (CVE-ID: CVE-2016-10012)

The vulnerability allows a local user to execute arbitrary code on vulnerable system with root privileges.

The vulnerability exists in sshd due to a flaw in boundary checks in the shared memory manager that may be skipped by some optimizing compilers. A local user can trigger memory corruption and execute arbitrary code with root privileges. The issue is related to m_zback and m_zlib data structures.

Successful exploitation of this vulnerability may allow a local user to elevate privileges.


3) Information disclosure (CVE-ID: CVE-2016-10011)

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to an error in authfile.c, which may allow a local authenticated user to obtain host private key material.

Successful exploitation of this vulnerability may allow a local user to gain access to otherwise restricted information.


4) Privilege escalation (CVE-ID: CVE-2016-10010)

The vulnerability allows a local user to execute arbitrary code on vulnerable system with root privileges.

The vulnerability exists due to an error in sshd in serverloop.c, which may allow a local authenticated user to execute arbitrary code with root privileges via a forwarded Unix-domain socket.

Successful exploitation of this vulnerability may allow a local user to elevate privileges.


5) Improper input validation (CVE-ID: CVE-2016-10009)

The vulnerability allows a remote attacker to execute arbitrary code on vulnerable ssh client.

The vulnerability exists due to incorrect handling of data passed to PKCS#11 module within ssh-agent. A remote attacker with control over sshd service can execute arbitrary code on vulnerable client.

Successful exploitation of this vulnerability may allow a remote attacker to execute arbitrary code on vulnerable client system but requires that client is connected to malicious SSH server.


Remediation

Install update from vendor's website.

References