CVE-2023-38240 in Acrobat Reader
Summary
by MITRE • 08/10/2023
Adobe Acrobat Reader versions 23.003.20244 (and earlier) and 20.005.30467 (and earlier) are affected by an out-of-bounds read vulnerability that could lead to disclosure of sensitive memory. An attacker could leverage this vulnerability to bypass mitigations such as ASLR. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/10/2023
Adobe Acrobat Reader contains a critical out-of-bounds read vulnerability that affects multiple versions including 23.003.20244 and earlier, as well as 20.005.30467 and earlier releases. This vulnerability resides in the document parsing functionality where the application fails to properly validate array indices when processing maliciously crafted PDF files. The flaw allows an attacker to read memory locations beyond the allocated buffer boundaries, potentially exposing sensitive information such as stack canaries, heap metadata, or other memory contents that could aid in bypassing security mitigations like address space layout randomization. The vulnerability is classified as a classic buffer over-read condition that falls under the CWE-125 weakness category, which represents out-of-bounds read errors in software implementations. This type of vulnerability creates opportunities for information disclosure attacks that can reveal memory layout details and potentially enable more sophisticated exploitation techniques.
The exploitation of this vulnerability requires social engineering to trick users into opening a maliciously crafted PDF file, making it a user-interaction dependent attack vector. When a victim opens the specially crafted document, the application processes the malformed data structure and triggers the out-of-bounds read condition. The memory disclosure aspect of this vulnerability is particularly concerning because it can expose memory addresses that are typically randomized by modern operating system security features. This information disclosure capability directly undermines ASLR protections, which rely on randomizing memory layout to prevent successful exploitation of other vulnerabilities. The attacker can leverage the leaked memory addresses to bypass security mitigations and potentially construct more effective exploits against the same or related targets.
The operational impact of this vulnerability extends beyond simple information disclosure to create a potential gateway for more serious attacks. Security researchers have noted that such memory disclosure vulnerabilities often serve as stepping stones for attackers to develop more sophisticated exploitation chains. The ability to bypass ASLR significantly increases the probability of successful exploitation of other vulnerabilities in the same application or related components. This vulnerability demonstrates how seemingly minor parsing issues can have cascading security implications, particularly in widely used applications like Adobe Acrobat Reader that process untrusted content from various sources. The vulnerability affects not only individual users but also enterprise environments where these applications are deployed across multiple systems, potentially creating widespread exposure if exploited at scale.
Organizations should prioritize immediate patching of affected Adobe Acrobat Reader installations to address this vulnerability. The recommended mitigation strategy involves updating to the latest available version that contains the necessary fixes for the out-of-bounds read condition. System administrators should also implement additional security measures such as restricting user permissions when opening PDF files, implementing content filtering solutions, and monitoring for suspicious file access patterns. Security teams should consider deploying application whitelisting policies to prevent execution of untrusted PDF files and establish incident response procedures for potential exploitation attempts. The vulnerability highlights the importance of keeping third-party applications updated and maintaining comprehensive software inventory management to quickly identify and remediate similar issues in other software components. Organizations should also consider implementing exploit prevention measures such as data execution prevention and heap-based buffer overflow protections to provide additional defense in depth against similar vulnerabilities.