Ubuntu update for libxdmcp

1) Key management errors

EUVDB-ID: #VU32096

Risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-2625

CWE-ID: CWE-320 - Key Management Errors

Exploit availability: No

Description

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

It was discovered that libXdmcp before 1.1.2 including used weak entropy to generate session keys. On a multi-user system using xdmcp, a local attacker could potentially use information available from the process list to brute force the key, allowing them to hijack other users' sessions.

Mitigation

Update the affected package libxdmcp to the latest version.

Vulnerable software versions

Ubuntu: 14.04 - 16.04

libxdmcp6 (Ubuntu package): before Ubuntu Pro (Infra-only)

CPE2.3

• cpe:2.3:o:canonical:ubuntu:14.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:16.04:*:*:*:*:*:*:*
• cpe:2.3:a:canonical:libxdmcp6_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-5690-1

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.