Advisory Details

July 30th, 2021

Foxit PDF Reader Annotation Use-After-Free Remote Code Execution Vulnerability

ZDI-21-934
ZDI-CAN-13929

CVE ID CVE-2021-34852
CVSS SCORE 7.8, AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AFFECTED VENDORS Foxit
AFFECTED PRODUCTS PDF Reader
VULNERABILITY DETAILS

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit PDF Reader. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the handling of Annotation objects. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process.

ADDITIONAL DETAILS Foxit has issued an update to correct this vulnerability. More details can be found at:
https://www.foxit.com/support/security-bulletins.html
DISCLOSURE TIMELINE
  • 2021-06-02 - Vulnerability reported to vendor
  • 2021-07-30 - Coordinated public release of advisory
  • 2021-08-03 - Advisory Updated
CREDIT Xu Peng from UCAS and Wang Yanhao from QiAnXin Technology Research Institute
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