Quantum Secular Labs / Blog / Advisories

CVE-2018-0487: Arm Mbed TLS: Buffer overflow

CVE-2018-0487 is rated critical with a CVSS v3.0 base score of 9.8 and affects Arm Mbed TLS, 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

ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0 allows remote attackers to execute arbitrary code or cause a denial of service (buffer overflow) via a crafted certificate chain that is mishandled during RSASSA-PSS signature verification within a TLS or DTLS session.

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

  • Arm Mbed TLS: from 1.3.8 before 1.3.22; from 2.1.0 before 2.1.10; from 2.2.0 before 2.7.0
  • Debian Linux: 8.0; 9.0

References