Buffer overflow in Comodo Antivirus

CVE-2019-3973

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.

Vulnerability class: Buffer Overflow

EPSS: 0.004 (31.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

  • Comodo Antivirus
  • N/a Comodo Antivirus — versions Versions 11.0.0.6582 and below

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-3973?
CVE-2019-3973 is a medium-severity vulnerability in Comodo Antivirus, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2019-07-17.
How severe is CVE-2019-3973?
Medium severity. CVSS v3 base score is 5.5 out of 10.