CVE-2018-5046 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader 2018.011.20040 and earlier, 2017.011.30080 and earlier, and 2015.006.30418 and earlier versions have an Out-of-bounds read vulnerability. Successful exploitation could lead to information disclosure.
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Analysis
by VulDB Data Team • 08/11/2024
Adobe Acrobat and Reader versions prior to 2018.011.20040, 2017.011.30080, and 2015.006.30418 contain a critical out-of-bounds read vulnerability that stems from improper input validation within the PDF parsing functionality. This vulnerability falls under the Common Weakness Enumeration category CWE-125, which describes out-of-bounds read conditions where an application accesses memory beyond the bounds of a buffer. The flaw occurs when processing maliciously crafted PDF files that contain malformed data structures, specifically within the document object model handling. When the vulnerable software attempts to parse certain PDF elements without adequate bounds checking, it reads data from memory locations that are not properly allocated for the intended operation. This particular vulnerability represents a classic buffer over-read condition that can be exploited by attackers who craft specially designed PDF documents to trigger the problematic code path. The technical implementation involves the software's failure to validate array indices or string lengths before accessing memory locations, allowing an attacker to potentially read sensitive data from adjacent memory regions.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can provide attackers with access to sensitive memory contents that may include encryption keys, user credentials, or other confidential data. Attackers can leverage this vulnerability through social engineering techniques by distributing malicious PDF files via email attachments, compromised websites, or malicious document repositories. When a user opens the crafted PDF file, the out-of-bounds read condition triggers automatically, potentially exposing system memory contents to unauthorized parties. This vulnerability aligns with the ATT&CK technique T1059.007 for command and scripting interpreter and T1566 for phishing, as it enables initial compromise through malicious document delivery. The exploitation typically requires no user interaction beyond opening the document, making it particularly dangerous in enterprise environments where users frequently open PDF files from external sources. The vulnerability affects multiple versions across different release cycles, indicating a persistent flaw in the PDF parsing engine that was not adequately addressed in the affected software versions.
Mitigation strategies for CVE-2018-5046 involve immediate patching of all affected Adobe Acrobat and Reader installations to the latest available versions that contain the necessary security fixes. Organizations should implement strict PDF file validation policies and consider deploying sandboxing technologies to isolate PDF processing activities from the primary operating system. Network security controls such as web proxies and email gateways should be configured to scan and block suspicious PDF files before they reach end users. Additionally, security awareness training should emphasize the importance of not opening PDF attachments from untrusted sources, as this vulnerability can be effectively exploited through phishing campaigns. The recommended remediation approach includes disabling PDF plugin support in web browsers where possible and implementing application whitelisting to prevent execution of unauthorized PDF processing applications. Security teams should also monitor for indicators of compromise related to this vulnerability and consider implementing intrusion detection systems that can identify attempts to exploit this specific out-of-bounds read condition. Regular vulnerability assessments should be conducted to identify any remaining instances of the affected software versions within the organization's infrastructure.