Quantum Secular Labs / Blog / Advisories

CVE-2018-17983: Mercurial: Memory corruption

CVE-2018-17983 is rated critical with a CVSS v3.0 base score of 9.1 and affects Mercurial. Per its scoring, it can be exploited over the network, without authentication, without any user interaction.

Vulnerability description

cext/manifest.c in Mercurial before 4.7.2 has an out-of-bounds read during parsing of a malformed manifest entry.

Severity breakdown

CVSS v3.0 9.1: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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: None. No loss of integrity.
  • 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

  • Mercurial: before 4.7.2

References