Quantum Secular Labs / Blog / Advisories

CVE-2017-12379: Clamav: Authentication bypass

CVE-2017-12379 is rated critical with a CVSS v3.0 base score of 9.8 and affects Clamav, along with 1 other product in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

ClamAV AntiVirus software versions 0.99.2 and prior contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or potentially execute arbitrary code on an affected device. The vulnerability is due to improper input validation checking mechanisms in the message parsing function on an affected system. An unauthenticated, remote attacker could exploit this vulnerability by sending a crafted email to the affected device. This action could cause a messageAddArgument (in message.c) buffer overflow condition when ClamAV scans the malicious email, allowing the attacker to potentially cause a DoS condition or execute arbitrary code on an affected device.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.

Affected products

  • Clamav: up to and including 0.99.2
  • Debian Linux: 7.0

References