Quantum Secular Labs / Blog / Advisories

CVE-2017-5949: Apple Safari: Buffer overflow

CVE-2017-5949 is rated critical with a CVSS v3.0 base score of 9.8 and affects Apple Safari. 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

JavaScriptCore in WebKit, as distributed in Safari Technology Preview Release 22, allows remote attackers to cause a denial of service (heap-based out-of-bounds write and application crash) or possibly have unspecified other impact via crafted JavaScript code that triggers access to red-zone memory locations, related to jit/ThunkGenerators.cpp, llint/LowLevelInterpreter32_64.asm, and llint/LowLevelInterpreter64.asm.

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-787: Out-of-bounds Write

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

Affected products

  • Apple Safari: 22

References