CVE-2017-2956 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 manipulation of the navigation pane. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 10/28/2022
The vulnerability identified as CVE-2017-2956 represents a critical use after free flaw within Adobe Acrobat Reader's JavaScript engine, affecting multiple version ranges including 15.020.20042 and earlier, 15.006.30244 and earlier, and 11.0.18 and earlier. This issue resides in the document processing component that handles JavaScript execution within PDF files, making it particularly dangerous as it can be triggered through malicious PDF documents. The vulnerability specifically manifests during navigation pane manipulation operations, where improper memory management allows attackers to exploit freed memory regions.
The technical nature of this flaw falls under CWE-416, which describes use after free conditions where memory is accessed after it has been freed, creating opportunities for memory corruption and arbitrary code execution. The JavaScript engine in Adobe Acrobat Reader processes PDF documents containing embedded scripts, and when manipulating the navigation pane elements, the engine fails to properly validate memory references, allowing attackers to craft malicious PDFs that trigger the vulnerable code path. This vulnerability operates at the intersection of memory safety issues and script execution contexts, making it particularly challenging to detect and prevent through traditional security measures.
The operational impact of CVE-2017-2956 extends beyond simple privilege escalation or denial of service scenarios, as successful exploitation can result in complete system compromise. Attackers can leverage this vulnerability to execute arbitrary code with the privileges of the Acrobat Reader process, which typically runs with user-level permissions but can potentially be escalated through additional attack vectors. The navigation pane manipulation aspect suggests that simply opening a malicious PDF document or navigating through its content could trigger the exploit, making it highly effective for phishing campaigns and targeted attacks. The vulnerability's presence in widely used software versions means that it affects numerous organizations and individuals who rely on Adobe Acrobat Reader for document viewing.
Mitigation strategies for this vulnerability should encompass multiple layers of defense including immediate patching of affected Adobe Acrobat Reader versions to the latest releases, implementing application whitelisting policies to restrict execution of untrusted PDF files, and deploying network-based intrusion detection systems that can identify suspicious PDF file patterns. The ATT&CK framework categorizes this vulnerability under technique T1059.007 for JavaScript execution, highlighting the need for comprehensive endpoint protection measures. Organizations should also consider implementing sandboxing technologies to isolate PDF processing operations and regularly audit their document handling procedures to minimize exposure to potentially malicious content. The vulnerability underscores the importance of maintaining current software versions and the necessity of robust security practices in preventing exploitation of memory corruption flaws in widely deployed applications.