CVE-2024-20748: 
Adobe Acrobat Reader Continuous vulnerability analysis and mitigation

Adobe Acrobat Reader versions 20.005.30539, 23.008.20470 and earlier contain an out-of-bounds read vulnerability (CVE-2024-20748) in the font file processing functionality. The vulnerability was discovered in February 2024 and affects the processing of OpenType font files embedded in PDF documents (Talos Report, Adobe Advisory).

The vulnerability exists in the processing of the Axis Variations (avar) table within OpenType font files. The issue occurs when the tableLength is less than the required size calculated by (0x08 + (0x02 axisCount) + (positionMapCount_1 4 + positionMapCount2 * 4 + ... + positionMapCountn * 4)). The comparison check for positionMapCount against the avar table tableLength is insufficient as it doesn't account for previously consumed bytes, leading to an out-of-bounds read condition. The vulnerability has been assigned a CVSS v3.1 base score of 5.5 (Medium) with vector: AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N (Talos Report).

This vulnerability could lead to the disclosure of sensitive memory information and potentially allow attackers to bypass security mitigations such as ASLR (Address Space Layout Randomization). The impact is limited to information disclosure without direct system compromise (NVD).

Adobe has released security updates to address this vulnerability. Users should update to the latest version of Adobe Acrobat and Reader (Adobe Advisory).