CVE-2019-3973 Information

Description

Comodo Antivirus versions 11.0.0.6582 and below are vulnerable to Denial of Service affecting CmdGuard.sys via its filter port \cmdServicePort. A low privileged process can crash CmdVirth.exe to decrease the port’s connection count followed by process hollowing a CmdVirth.exe instance with malicious code to obtain a handle to \cmdServicePort. Once this occurs a specially crafted message can be sent to \cmdServicePort\ using \FilterSendMessage\ API. This can trigger an out-of-bounds write if lpOutBuffer parameter in FilterSendMessage API is near the end of specified buffer bounds. The crash occurs when the driver performs a memset operation which uses a size beyond the size of buffer specified causing kernel crash.

CVSS Vector

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Reference

https://www.tenable.com/security/research/tra-2019-34

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

5.5