2021-34845 | Foxit PDF Reader Annotation Object use after free

By Max On Aug 8, 2021

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6.7	$0-$5k	0.57

A vulnerability has been found in Foxit PDF Reader 11.0.0.49893 (Document Reader Software) and classified as critical. Affected by this vulnerability is an unknown function of the component Annotation Object Handler. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-416. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Foxit PDF Reader 11.0.0.49893. 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. Was ZDI-CAN-14034.

The weakness was presented 08/05/2021. It is possible to read the advisory at zerodayinitiative.com. This vulnerability is known as CVE-2021-34845 since 06/17/2021. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn’t need any form of authentication. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available.

Upgrading eliminates this vulnerability.

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