CVE-2018-4948 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 and earlier have a Heap Overflow vulnerability. Successful exploitation could lead to arbitrary code execution in the context of the current user.
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Analysis
by VulDB Data Team • 03/13/2023
Adobe Acrobat and Reader applications contain a critical heap overflow vulnerability that affects multiple version ranges including 2018.011.20038 and earlier, 2017.011.30079 and earlier, and 2015.006.30417 and earlier. This vulnerability arises from insufficient bounds checking when processing specially crafted pdf files, specifically within the memory management routines that handle heap allocations. The flaw manifests when the application attempts to write data beyond the allocated memory boundaries, creating a condition where attacker-controlled input can overwrite adjacent memory locations. This heap overflow represents a direct violation of memory safety principles and falls under the CWE-121 heap-based buffer overflow category. The vulnerability enables an attacker to execute arbitrary code with the privileges of the currently logged-in user, effectively providing a complete compromise of the affected system. When exploited, this vulnerability allows for privilege escalation attacks that can bypass standard security controls and establish persistent access to the target environment.
The operational impact of this vulnerability extends beyond simple code execution, as it creates a significant attack surface that can be leveraged through various delivery mechanisms including malicious email attachments, compromised websites, or social engineering campaigns. Attackers can craft specially formatted pdf documents that trigger the heap overflow when opened by vulnerable applications, making this vulnerability particularly dangerous in enterprise environments where pdf files are commonly shared and opened. The exploitation process typically involves careful crafting of input data that causes the application to allocate insufficient memory for processing, followed by overflow that can overwrite critical program pointers or return addresses. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under the execution and privilege escalation domains, specifically targeting the use of malicious files and exploitation of software vulnerabilities. The memory corruption resulting from this heap overflow can be exploited to redirect program execution flow, potentially leading to remote code execution or local privilege escalation.
Mitigation strategies for CVE-2018-4948 should focus on immediate patching of all affected Adobe Acrobat and Reader installations, as Adobe released security updates to address this vulnerability. Organizations should implement strict pdf file handling policies that include sandboxing mechanisms, content filtering, and restricted user permissions when processing pdf documents. Network-based defenses such as web application firewalls and email security solutions can help detect and block malicious pdf files before they reach end users. Additionally, system hardening measures including address space layout randomization, data execution prevention, and heap protection mechanisms can provide additional layers of defense against exploitation attempts. Security monitoring should include detection of suspicious pdf file access patterns and abnormal memory usage that may indicate exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to ensure that all endpoints remain protected against similar heap-based vulnerabilities, as this class of vulnerability frequently appears in software applications that handle complex file formats. The remediation process must also include user education regarding the risks of opening untrusted pdf documents and the importance of keeping software updated.