CVE-2019-7796 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2019.010.20100 and earlier, 2019.010.20099 and earlier, 2017.011.30140 and earlier, 2017.011.30138 and earlier, 2015.006.30495 and earlier, and 2015.006.30493 and earlier have an use after free vulnerability. Successful exploitation could lead to arbitrary code execution.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/16/2024
The vulnerability identified as CVE-2019-7796 represents a critical use after free flaw affecting multiple versions of Adobe Acrobat and Reader software. This vulnerability manifests in the handling of memory management within the affected applications, specifically when processing certain PDF documents. The flaw occurs when the software attempts to access memory that has already been freed, creating a scenario where malicious actors can manipulate the application's memory state to execute arbitrary code. Such vulnerabilities are particularly dangerous because they can be exploited remotely through crafted PDF files delivered via email attachments, web downloads, or malicious websites.
The technical implementation of this use after free vulnerability stems from improper memory management practices within the PDF parsing components of Adobe Acrobat and Reader. When processing maliciously crafted PDF content, the software allocates memory for objects and subsequently frees that memory without properly nullifying pointers. Attackers can exploit this by carefully constructing PDF files that trigger the freeing of memory while maintaining references to that freed memory space. This creates a condition where the attacker can control what data is placed in the freed memory location and subsequently cause the application to execute that controlled data as code. The vulnerability is categorized under CWE-416, which specifically addresses use after free conditions in software implementations.
The operational impact of CVE-2019-7796 extends beyond simple code execution, as it provides attackers with a complete remote code execution capability within the context of the user's session. This vulnerability can be leveraged to bypass security controls, escalate privileges, and potentially establish persistent access to target systems. The affected versions span multiple release cycles, indicating this flaw has remained unpatched for an extended period, increasing the attack surface significantly. Organizations running these vulnerable versions face substantial risk as the exploitation requires minimal user interaction beyond opening a malicious document, making it particularly attractive to threat actors. The vulnerability aligns with ATT&CK technique T1203, which involves exploiting software vulnerabilities to gain unauthorized access, and T1059, which covers command and scripting interpreters for execution.
Mitigation strategies for CVE-2019-7796 primarily focus on immediate patch management and operational security measures. Adobe has released security updates addressing this vulnerability in newer versions of Acrobat and Reader, making it imperative for organizations to deploy these patches as soon as possible. Until patches are applied, organizations should implement strict email filtering, disable PDF processing in web browsers, and employ sandboxing techniques to isolate potentially malicious documents. Network-based intrusion detection systems should be configured to monitor for PDF-related anomalies, and user education regarding suspicious email attachments remains crucial. The vulnerability demonstrates the importance of maintaining current software versions and implementing comprehensive vulnerability management processes to prevent exploitation of known flaws. Security teams should also consider implementing application whitelisting policies to restrict execution of untrusted PDF files and conduct regular vulnerability assessments to identify similar memory corruption issues in other software components.