SB2019080850 - Fedora EPEL 7 update for libmspack



SB2019080850 - Fedora EPEL 7 update for libmspack

Published: August 8, 2019 Updated: April 25, 2025

Security Bulletin ID SB2019080850
Severity
High
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Out-of-bounds write (CVE-ID: CVE-2018-18584)

The vulnerability allows a remote attacker to cause DoS condition or execute arbitrary code on the target system.

The vulnerability exists in the mspack/cab.h source code file due to Microsoft cabinet file (CAB) with a Quantum-compressed block of exactly 38,912 B will write 1 B beyond the end of the input buffer. when handling malicious input. A remote unauthenticated attacker can trick the victim into accessing of a CAB file that submits malicious input to the targeted system, trigger an out-of-bounds write condition and cause the application to crash or execute arbitrary code with elevated privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


2) Null pointer dereference (CVE-ID: CVE-2018-18585)

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to  the chmd_read_headers function, as defined in the mspack/chmd.c source code file of the affected software, accepts filenames that have embedded NULL bytes. A remote attacker can trick the victim into accessing a Compiled HTML (CHM) file that submits malicious input to the targeted system, trigger NULL pointer dereference and cause the service to crash.


Remediation

Install update from vendor's website.