CVE-2012-0685 in XnView
Summary
by MITRE
Integer overflow in XnViewer (aka XnView) before 1.98.5 allows remote attackers to execute arbitrary code via a crafted file containing PSD record types, a different vulnerability than CVE-2012-0684.
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Analysis
by VulDB Data Team • 12/01/2021
The vulnerability identified as CVE-2012-0685 represents a critical integer overflow flaw within XnViewer, a popular image viewing and editing application. This vulnerability specifically affects versions prior to 1.98.5 and stems from improper handling of PSD (Photoshop Document) file structures during the parsing of record types. The flaw exists in the application's image processing engine where it fails to properly validate integer values when processing certain PSD file components, creating a condition where arithmetic operations can exceed the maximum representable value for signed integers. This type of vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, which is a well-documented weakness in software security. The vulnerability is distinct from CVE-2012-0684, indicating that attackers can leverage different attack vectors to achieve arbitrary code execution within the target system.
The technical implementation of this vulnerability occurs when XnViewer processes specially crafted PSD files that contain maliciously constructed record types. During the parsing process, the application attempts to calculate buffer sizes or array indices based on data extracted from the PSD file headers. When these values exceed the maximum limit of a 32-bit signed integer, the overflow causes unexpected behavior in memory allocation or array indexing operations. Attackers can exploit this by creating PSD files with carefully manipulated record size fields that, when processed by the vulnerable application, trigger the integer overflow condition. This overflow can result in heap-based buffer overflows or stack corruption, which in turn allows attackers to overwrite critical memory locations and execute arbitrary code with the privileges of the user running the application. The attack vector is remote, meaning that an attacker can deliver the malicious file through email attachments, web downloads, or other network-based delivery mechanisms without requiring local access to the target system.
The operational impact of CVE-2012-0685 extends beyond simple code execution, as it provides attackers with a potential foothold for more sophisticated attacks within the target environment. When successfully exploited, the vulnerability enables attackers to gain arbitrary code execution capabilities, potentially allowing them to install malware, establish persistent backdoors, or escalate privileges within the compromised system. The vulnerability affects users who may inadvertently open malicious PSD files, making it particularly dangerous in corporate or educational environments where users frequently exchange image files. The attack can be particularly effective against users running older versions of XnViewer, as these installations are more likely to be exposed to the vulnerability. Additionally, the vulnerability's remote nature means that attackers can target users without requiring physical access to their systems, making it a significant concern for organizations with distributed user bases or those that rely on image sharing platforms.
The mitigation strategy for CVE-2012-0685 focuses primarily on updating to the patched version of XnViewer, specifically version 1.98.5 or later, which addresses the integer overflow condition through proper input validation and boundary checking. Organizations should implement comprehensive patch management procedures to ensure all systems running XnViewer are updated promptly. Additionally, security-conscious organizations may consider implementing file type restrictions or content filtering mechanisms that prevent the automatic execution of potentially malicious image files. Network administrators can deploy intrusion detection systems that monitor for suspicious file handling patterns or attempts to access known vulnerable applications. From a defensive perspective, the vulnerability demonstrates the importance of input validation in image processing libraries and highlights the need for robust integer overflow protection mechanisms. This aligns with ATT&CK framework techniques related to exploitation of software vulnerabilities and privilege escalation, as the initial compromise through code execution can lead to further system compromise. Organizations should also consider implementing application whitelisting policies that restrict execution of untrusted image processing applications, particularly in environments where users may be exposed to unverified file content. The vulnerability serves as a reminder of the critical importance of regular security updates and the potential risks associated with legacy software that may not receive ongoing security support.