Quantum Secular Labs / Blog / Advisories

CVE-2017-9058: Ytnef Project: Buffer overflow

CVE-2017-9058 is rated critical with a CVSS v3.0 base score of 9.8 and affects Ytnef Project, 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

In libytnef in ytnef through 1.9.2, there is a heap-based buffer over-read due to incorrect boundary checking in the SIZECHECK macro in lib/ytnef.c.

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-125: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

Affected products

  • Ytnef Project: up to and including 1.9.2
  • Canonical Ubuntu Linux: 14.04

References