CVE-2018-12847 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 a heap overflow vulnerability. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 08/08/2024
Adobe Acrobat and Reader applications contain a critical heap overflow vulnerability that affects multiple version ranges including 2018.011.20063 and earlier, 2017.011.30102 and earlier, and 2015.006.30452 and earlier. This vulnerability stems from improper input validation within the software's handling of malformed PDF files, creating a condition where an attacker can manipulate memory allocation patterns to trigger unauthorized code execution. The heap overflow occurs when the application processes specially crafted PDF content that exceeds expected buffer boundaries, potentially allowing malicious actors to overwrite adjacent memory locations with attacker-controlled data. This flaw represents a significant security risk as it can be exploited through social engineering attacks where users open maliciously crafted PDF files, making it particularly dangerous in enterprise environments where document sharing is common.
The technical implementation of this vulnerability falls under the Common Weakness Enumeration category CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to write beyond allocated memory regions. The attack vector typically involves crafting a malicious PDF document that triggers the vulnerable code path when the application attempts to parse or render specific elements within the document structure. When the heap overflow occurs, it can corrupt critical program data structures including return addresses, function pointers, or other control flow information that enables attackers to redirect execution to malicious code. This vulnerability aligns with ATT&CK technique T1203, which involves gaining access to execution capabilities through exploitation of software vulnerabilities, and T1059, which covers the use of command and scripting interpreters to execute malicious code.
The operational impact of this vulnerability extends beyond individual user compromise to potentially affect entire organizational networks where Adobe Reader is widely deployed. Organizations that rely heavily on PDF document processing for business operations face significant risk as attackers can leverage this vulnerability to establish persistent access, escalate privileges, or conduct data exfiltration activities. The vulnerability's exploitation potential increases when considering that PDF documents can be delivered through multiple channels including email attachments, web downloads, and file sharing platforms, making it difficult to control the attack surface. Security teams must also consider the challenge of maintaining visibility into PDF processing activities within their networks, as the vulnerability can be exploited without requiring specialized tools or extensive reconnaissance.
Organizations should prioritize immediate remediation by updating to patched versions of Adobe Acrobat and Reader, with the specific versions containing fixes for this vulnerability being released after the affected versions mentioned in the CVE description. Additionally, implementing multiple layers of defense-in-depth strategies can help mitigate risk while waiting for patches to be deployed, including restricting PDF file handling through network firewalls, implementing sandboxing technologies for PDF processing, and deploying email filtering solutions that can detect and block potentially malicious PDF attachments. Network monitoring should be enhanced to detect unusual PDF processing activities that may indicate exploitation attempts, and user education programs should be strengthened to reduce the likelihood of successful social engineering attacks. The vulnerability also highlights the importance of maintaining up-to-date security patches across all software platforms, particularly those handling untrusted content, as this represents a classic example of how legacy software vulnerabilities can persist and remain exploitable for years after initial discovery.