CVE-2017-2957 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat Reader versions 15.020.20042 and earlier, 15.006.30244 and earlier, 11.0.18 and earlier have an exploitable use after free vulnerability in the JavaScript engine, related to collaboration functionality. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 09/01/2024
The vulnerability identified as CVE-2017-2957 represents a critical use after free flaw within Adobe Acrobat Reader's JavaScript engine implementation. This security defect affects multiple versions of the software including those in the 15.020.x, 15.006.x, and 11.0.18 release series, making it a widespread concern across various Acrobat Reader deployments. The vulnerability specifically manifests within the collaboration functionality of the application, which is commonly used for document sharing and annotation features. The JavaScript engine serves as the execution environment for interactive PDF elements, making it a prime target for exploitation by malicious actors seeking to compromise systems through document-based attacks.
The technical nature of this vulnerability stems from improper memory management within the JavaScript engine where freed memory blocks are still being referenced or accessed by subsequent operations. When a JavaScript object or memory allocation is freed but the application continues to reference that memory location, attackers can manipulate the freed memory to execute arbitrary code. This particular flaw occurs during the processing of collaborative features such as comments, annotations, or shared review workflows. The use after free condition creates a scenario where attackers can overwrite or corrupt memory contents with malicious payloads, potentially leading to complete system compromise. According to CWE classification, this vulnerability maps to CWE-416 which specifically addresses the use of freed memory, a category that has historically proven to be one of the most dangerous memory corruption vulnerabilities in software applications.
The operational impact of CVE-2017-2957 extends beyond simple exploitation as it represents a significant threat vector for advanced persistent threats and targeted attacks. Attackers leveraging this vulnerability can achieve remote code execution without requiring user interaction beyond opening a malicious PDF document, making it particularly dangerous in enterprise environments where users frequently open documents from external sources. The collaboration features in Acrobat Reader are commonly used in business settings for document review processes, making this vulnerability particularly attractive to threat actors conducting corporate espionage or ransomware campaigns. The vulnerability's exploitability is enhanced by the fact that it requires no special privileges or complex attack chains, allowing adversaries to achieve system compromise through simple document manipulation. Organizations using older versions of Acrobat Reader face substantial risk as these vulnerable versions continue to be deployed in legacy systems where immediate patching is not feasible.
Mitigation strategies for CVE-2017-2957 primarily focus on immediate remediation through software updates and patches provided by Adobe. The most effective approach involves upgrading to Adobe Acrobat Reader versions that have addressed this specific memory management flaw, typically those released after the vulnerability disclosure date. Organizations should implement comprehensive patch management procedures to ensure all instances of Acrobat Reader are updated across their networks. Network-based mitigations can include PDF file filtering and sandboxing mechanisms that restrict the execution of potentially malicious JavaScript code within PDF documents. The implementation of the ATT&CK framework's T1203 technique, which involves process injection and memory manipulation, highlights the need for memory protection mechanisms such as address space layout randomization and data execution prevention. Additionally, security awareness training for end users regarding the dangers of opening untrusted PDF documents remains crucial, as social engineering remains a common delivery method for exploits targeting this vulnerability category.