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Use After Free

CVE-2021-40420

High
8.8/10

Summary

A use-after-free vulnerability exists in the JavaScript engine of Foxit Software’s PDF Reader, version 11.1.0.52543. A specially-crafted PDF document can trigger the reuse of previously freed memory, which can lead to arbitrary code execution. An attacker needs to trick the user to open the malicious file to trigger this vulnerability. Exploitation is also possible if a user visits a specially-crafted, malicious site if the browser plugin extension is enabled.

  • LOW
  • NETWORK
  • HIGH
  • UNCHANGED
  • REQUIRED
  • NONE
  • HIGH
  • HIGH

CWE-416 - Use After Free

Use-after-free (UaF) vulnerability occurs when the application is using a pointer to memory that has been freed. Any attempt to read/write to a buffer after it is de-allocated allows memory corruption, sensitive information exposure, and can potentially lead to arbitrary code execution.

References

Advisory Timeline

  • Published