CVE-2019-7788 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 a use after free vulnerability. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 06/16/2024
The vulnerability identified as CVE-2019-7788 represents a critical use after free flaw affecting multiple versions of Adobe Acrobat and Reader software. This issue manifests in the handling of memory management within the affected applications, specifically when processing certain PDF files. The vulnerability falls under the CWE-416 category of Use After Free, which occurs when a program continues to reference memory after it has been freed, potentially allowing attackers to manipulate the freed memory location for malicious purposes. The affected versions span across several release cycles including 2019.010.20100 and earlier, 2017.011.30140 and earlier, and 2015.006.30495 and earlier, indicating this flaw has persisted across multiple software iterations. The exploitation of this vulnerability can lead to arbitrary code execution, making it particularly dangerous for end users who may inadvertently open malicious PDF documents.
The technical implementation of this use after free vulnerability occurs during the processing of PDF objects within the Adobe Reader environment. When the application encounters specific malformed PDF structures, it may free memory associated with certain objects while still maintaining references to that memory location. This creates a window where an attacker can overwrite the freed memory with malicious data, potentially redirecting program execution flow. The vulnerability is particularly concerning because PDF documents are commonly shared through email attachments, web downloads, and document repositories, making exploitation vectors abundant. Attackers can craft specially designed PDF files that trigger the memory corruption when opened, potentially executing shellcode or other malicious payloads directly on the victim's system.
From an operational perspective, the impact of CVE-2019-7788 extends beyond simple code execution, as it can enable complete system compromise. The vulnerability's exploitation aligns with ATT&CK technique T1203, which involves gaining access to systems through malicious document manipulation. Organizations relying on Adobe Reader for document viewing face significant risk, as the attack surface is broad and the attack vector is easily accessible through common communication channels. The vulnerability can be leveraged for privilege escalation, data exfiltration, or as a foothold for further network infiltration. Given that Adobe Reader remains widely deployed across enterprise environments, the potential for widespread exploitation exists, particularly in environments where users have default permissions to open PDF files without proper security controls.
Mitigation strategies for CVE-2019-7788 primarily focus on immediate software updates and operational security measures. Adobe has released patches for all affected versions, making it essential for organizations to deploy these updates promptly through their standard patch management procedures. Security professionals should implement additional controls such as PDF sandboxing, restricted file type handling, and network-based filtering to prevent malicious documents from reaching end users. The vulnerability's characteristics make it suitable for exploitation in targeted attacks, so organizations should consider implementing email filtering solutions that can detect and block suspicious PDF attachments. Additionally, user education programs should emphasize the importance of only opening PDF files from trusted sources and avoiding unexpected document attachments. Network segmentation and application whitelisting can provide additional layers of protection, ensuring that even if exploitation occurs, the attack scope remains limited. Organizations should also consider implementing automated vulnerability scanning tools to identify systems running unpatched versions of Adobe Reader, as this vulnerability remains exploitable in older software releases.