CVE-2015-4443 in Acrobat Reader
Summary
by MITRE
Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC Classic before 2015.006.30060, and Acrobat and Acrobat Reader DC Continuous before 2015.008.20082 on Windows and OS X allow attackers to cause a denial of service (NULL pointer dereference) via unspecified vectors, a different vulnerability than CVE-2015-4444.
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Analysis
by VulDB Data Team • 06/01/2022
Adobe Reader and Acrobat versions prior to specific patch levels contain a critical null pointer dereference vulnerability that enables remote attackers to trigger a denial of service condition. This vulnerability affects multiple product lines including Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, as well as various Acrobat Reader DC Classic and Continuous versions. The flaw manifests when the software processes malformed or specially crafted input data, causing the application to attempt to dereference a null pointer reference. This type of vulnerability falls under CWE-476 which specifically addresses null pointer dereference conditions that can lead to application crashes or system instability.
The technical implementation of this vulnerability occurs within the document processing engine of Adobe's PDF rendering components. When an attacker crafts a malicious PDF document containing malformed data structures or unexpected input sequences, the application's parsing routines fail to properly validate pointer references before accessing them. This allows the execution flow to proceed to a memory location that has not been properly initialized, resulting in a segmentation fault or access violation that terminates the application process. The vulnerability is particularly concerning because it can be triggered through legitimate document viewing scenarios, making it an attractive target for social engineering attacks where users might unknowingly open malicious files.
The operational impact of CVE-2015-4443 extends beyond simple application crashes to potentially disrupt business operations in environments where Adobe Reader is extensively used. Organizations relying on PDF document processing for critical workflows may experience service interruptions when attackers exploit this vulnerability through email attachments, web downloads, or shared network resources. The vulnerability's persistence across multiple product versions and operating systems including both Windows and OS X platforms creates a broad attack surface that security teams must address. This type of denial of service vulnerability aligns with ATT&CK technique T1499 which covers network denial of service attacks and can be leveraged as part of broader attack campaigns targeting enterprise environments.
Mitigation strategies for this vulnerability should prioritize immediate patch deployment to the affected versions of Adobe Reader and Acrobat software. Organizations should implement network-based controls such as PDF file filtering at perimeter defenses to prevent potentially malicious documents from entering the network. Security teams should also consider implementing application whitelisting policies that restrict execution of Adobe Reader to trusted environments and versions. Additionally, user education regarding suspicious email attachments and untrusted document sources remains crucial in preventing exploitation. Regular vulnerability assessments and penetration testing should be conducted to identify similar null pointer dereference conditions in other software components within the organization's attack surface. The remediation process should include comprehensive testing of patched versions to ensure that the vulnerability is properly resolved without introducing regressions in functionality.