SB2018032209 - Multiple vulnerabilities in heimdal

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Incorrect permission assignment for critical resource (CVE-ID: CVE-2018-5349)

The vulnerability allows a local authenticated user to execute arbitrary code.

A vulnerability has been found in Heimdal PRO v2.2.190, but it is most likely also present in Heimdal FREE and Heimdal CORP. Faulty permissions on the directory "C:ProgramDataHeimdal SecurityHeimdal Agent" allow BUILTINUsers to write new files to the directory. On startup, the process Heimdal.MonitorServices.exe running as SYSTEM will attempt to load version.dll from this directory. Placing a malicious version.dll in this directory will result in privilege escalation. NOTE: any affected Heimdal products are completely unrelated to the Heimdal vendor of a Kerberos 5 product on the h5l.org web site.

2) Input validation error (CVE-ID: CVE-2018-5731)

The vulnerability allows a local authenticated user to execute arbitrary code.

An issue was discovered in Heimdal PRO 2.2.190. As part of the scanning feature, a process called md.hs writes an executable called CS1.tmp to C:windowsTEMP. Afterwards the executable is run. It is possible for an attacker to create the file first, let md.hs overwrite it, and then rewrite the file in the window between md.hs closing the file and executing it. This can be exploited via opportunistic locks and a high priority thread. The vulnerability is triggered when a scan starts. NOTE: any affected Heimdal products are completely unrelated to the Heimdal vendor of a Kerberos 5 product on the h5l.org web site.

Remediation

Install update from vendor's website.

References

• https://improsec.com/blog/heimdal-advisory-1
• https://improsec.com/blog/heimdal-advisory-2