SB2018012203 - Ubuntu update for OpenSSH
Published: January 22, 2018
Security Bulletin ID
SB2018012203
Severity
Low
Patch available
YES
Number of vulnerabilities
5
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 secuirty vulnerabilities.
1) 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.
2) 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.
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) 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.
5) Denial of service (CVE-ID: CVE-2017-15906)
The vulnerability allows a remote authenticated attacker to cause DoS condition on the target system.The weakness exists in the process_open() function due to improper prevention of write operations in read-only mode. A remote attacker can create zero-length files and cause the service to crash.
Successful exploitation of the vulnerability results in denial of service.
Remediation
Install update from vendor's website.