Quantum Secular Labs / Blog / Advisories

CVE-2018-1000217: Davegamble Cjson: Use after free

CVE-2018-1000217 is rated critical with a CVSS v3.0 base score of 9.8 and affects Davegamble Cjson. 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

Dave Gamble cJSON version 1.7.3 and earlier contains a CWE-416: Use After Free vulnerability in cJSON library that can result in Possible crash, corruption of data or even RCE. This attack appear to be exploitable via Depends on how application uses cJSON library. If application provides network interface then can be exploited over a network, otherwise just local.. This vulnerability appears to have been fixed in 1.7.4.

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-416: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

Affected products

  • Davegamble Cjson: before 1.7.4

References