CVE-2018-17282 in Exiv2
Summary
by MITRE
An issue was discovered in Exiv2 v0.26. The function Exiv2::DataValue::copy in value.cpp has a NULL pointer dereference.
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Analysis
by VulDB Data Team • 05/17/2023
The vulnerability identified as CVE-2018-17282 represents a critical NULL pointer dereference flaw within the Exiv2 image metadata processing library version 0.26. This issue occurs in the Exiv2::DataValue::copy function located in the value.cpp source file, which forms a fundamental component of the library's metadata handling capabilities. Exiv2 is widely utilized across numerous applications and systems for reading and writing image metadata, making this vulnerability particularly concerning from a security perspective.
The technical nature of this flaw stems from inadequate input validation within the DataValue::copy function, which fails to properly handle cases where pointer values may be null during metadata processing operations. When an application utilizing Exiv2 encounters malformed or specially crafted image files, the library's internal state can lead to a situation where a null pointer is dereferenced during the copy operation. This condition results in an immediate application crash or potential denial of service condition, as the program attempts to access memory at address zero or an invalid memory location.
The operational impact of this vulnerability extends beyond simple application instability, as it can be exploited by malicious actors to disrupt services through carefully crafted image files. Systems that process user-uploaded images or automatically parse metadata from external sources become particularly vulnerable to this attack vector. The flaw demonstrates characteristics consistent with CWE-476, which specifically addresses NULL pointer dereference conditions in software implementations. This vulnerability type is particularly dangerous in environments where Exiv2 is integrated into web applications, content management systems, or digital asset management platforms that process untrusted image data from multiple sources.
From an adversary perspective, this vulnerability aligns with ATT&CK technique T1203, which involves exploiting application vulnerabilities to gain unauthorized access or disrupt system operations. The attack surface is broad given Exiv2's extensive adoption across various software ecosystems, including but not limited to web browsers, image processing applications, and server-side content management solutions. The exploitation requires minimal complexity as it only necessitates the delivery of a specially crafted image file that triggers the null pointer dereference during metadata parsing operations.
Mitigation strategies should prioritize immediate patching of affected systems with updated Exiv2 versions that address the NULL pointer dereference issue. Organizations should implement comprehensive input validation and sanitization measures when processing image metadata, particularly in environments where untrusted user uploads are common. Additionally, deployment of network-based intrusion detection systems that can identify and block malicious image file patterns may provide additional defense layers. System administrators should conduct thorough vulnerability assessments to identify all applications and services utilizing Exiv2, ensuring that proper monitoring and alerting mechanisms are in place to detect potential exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date third-party libraries and implementing robust security testing practices that include static code analysis and dynamic vulnerability scanning to prevent similar issues from arising in future software releases.