CVE-2018-15920 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 and earlier have an use after free vulnerability. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 08/08/2024
The vulnerability identified as CVE-2018-15920 represents a critical use after free flaw affecting Adobe Acrobat and Reader software across multiple version lines including 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 and earlier. This type of vulnerability occurs when a program continues to reference memory that has already been freed, creating a condition where attackers can manipulate the program's execution flow. The flaw falls under the Common Weakness Enumeration category CWE-416, which specifically addresses use after free conditions that can lead to memory corruption vulnerabilities. The vulnerability stems from improper memory management within the PDF processing components of Adobe's software suite, where objects are deallocated from memory but the application continues to reference them, creating opportunities for exploitation.
The exploitation of this use after free vulnerability can result in arbitrary code execution, making it particularly dangerous for end users and organizations. When an attacker successfully triggers this condition, they can manipulate the program's memory layout to inject and execute malicious code with the privileges of the affected application. This typically occurs when processing specially crafted PDF files that contain malformed data structures designed to trigger the memory management error. The attack vector involves constructing a malicious PDF document that, when opened by the vulnerable Adobe application, causes the program to free memory associated with a particular object and then subsequently reference that same memory location. The operational impact extends beyond simple code execution to include potential privilege escalation, data theft, and system compromise, as the malicious code runs within the context of the Adobe application process.
Security researchers have identified that this vulnerability aligns with several tactics outlined in the MITRE ATT&CK framework, particularly those related to initial access and execution phases. The vulnerability can be leveraged through social engineering campaigns where users are tricked into opening malicious PDF attachments, making it a common target for phishing attacks and targeted malware delivery. Organizations that rely heavily on Adobe Acrobat and Reader for document processing face significant risk exposure, as these applications are frequently used to open documents from untrusted sources. The vulnerability's impact is amplified by the widespread adoption of Adobe's software across enterprise environments, where a successful exploitation could provide attackers with persistent access to sensitive corporate data. Additionally, the vulnerability's characteristics make it suitable for exploitation in zero-day attack scenarios, as the memory corruption behavior can be difficult to detect through traditional signature-based security mechanisms.
The recommended mitigation strategies for CVE-2018-15920 primarily focus on immediate software updates and operational security measures. Adobe has released patches for all affected versions, and organizations should prioritize updating to the latest available versions of Acrobat and Reader to eliminate the vulnerability. System administrators should implement network-based protections such as PDF content filtering and sandboxing solutions to prevent exploitation attempts before they can succeed. Additional mitigations include disabling JavaScript execution within PDF documents, implementing strict file type restrictions, and employing application whitelisting policies to prevent execution of unauthorized code. Organizations should also consider deploying intrusion detection systems that can monitor for suspicious PDF processing activities and network traffic patterns associated with exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of vulnerable software within the organization's environment, as the use after free condition can persist even after initial exploitation attempts have been mitigated.