CVE-2021-21056: 
Adobe Framemaker vulnerability analysis and mitigation

Adobe FrameMaker version 2020.0.1 and earlier versions are affected by an Out-of-bounds Read vulnerability when parsing specially crafted files. The vulnerability was assigned CVE-2021-21056 and was disclosed in March 2021. This security flaw affects Adobe FrameMaker installations on Microsoft Windows systems (Adobe Advisory).

The vulnerability is classified as an Out-of-bounds Read (CWE-125) that occurs during PDF file parsing. When parsing a specially crafted PDF file, the application can trigger a read operation past the end of an allocated buffer. The vulnerability has received a CVSS v3.0 base score of 7.8 HIGH with the vector string CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H (ZDI Advisory).

A successful exploitation of this vulnerability could allow an attacker to execute arbitrary code in the context of the current user. The vulnerability affects confidentiality, integrity, and availability of the system, with potential for complete compromise of the affected system (ZDI Advisory).

The vulnerability requires user interaction to be exploited, as the target must open a malicious file. An unauthenticated attacker could leverage this vulnerability through a specially crafted PDF file. The attack complexity is considered low, indicating that the exploitation is straightforward once the user interaction requirement is met (Adobe Advisory).

Adobe has released security updates to address this vulnerability. Users are advised to update to the latest version of Adobe FrameMaker. The fix was released as part of Adobe's security bulletin APSB21-14 (Adobe Advisory).