CVE-2017-14858 in Exiv2
Summary
by MITRE
There is a heap-based buffer overflow in the Exiv2::l2Data function of types.cpp in Exiv2 0.26. A Crafted input will lead to a denial of service attack.
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Analysis
by VulDB Data Team • 03/04/2025
The heap-based buffer overflow vulnerability identified in CVE-2017-14858 resides within the Exiv2 library version 0.26, specifically within the Exiv2::l2Data function located in the types.cpp file. This vulnerability represents a critical security flaw that can be exploited through carefully crafted input data, potentially leading to system compromise and denial of service conditions. The Exiv2 library serves as a crucial component for image metadata handling across numerous applications and systems, making this vulnerability particularly concerning for widespread impact. The vulnerability manifests when the library processes malformed image data, specifically targeting the memory allocation patterns within the l2Data function. This function is responsible for handling certain data types within image metadata, and the improper bounds checking creates an opportunity for attackers to manipulate heap memory through malicious input sequences. The flaw falls under the category of CWE-121 heap-based buffer overflow, which is classified as a serious memory safety issue that can lead to arbitrary code execution or system instability. When exploited, this vulnerability allows attackers to manipulate the heap memory layout, potentially causing application crashes or enabling more sophisticated attack vectors. The vulnerability is particularly dangerous because Exiv2 is widely used across various software platforms, including web applications, image processing tools, and content management systems, making it a prime target for attackers seeking to exploit the widespread adoption of this library.
The technical implementation of this vulnerability involves the manipulation of input data that triggers improper memory handling within the Exiv2::l2Data function. When the library encounters crafted input sequences, it fails to properly validate the size of data being processed against allocated heap memory boundaries. This leads to memory corruption where the program attempts to write beyond the allocated buffer space, potentially overwriting adjacent memory locations. The heap-based nature of this overflow means that the corruption occurs in dynamic memory allocated during program execution rather than in stack-based buffers, making detection and exploitation more complex. The vulnerability can be triggered through image files that contain specially constructed metadata fields, particularly those related to image type handling within the Exiv2 library. Attackers can craft input files that cause the library to allocate insufficient memory for processing certain data types, then write beyond these boundaries to corrupt heap structures. This type of vulnerability is particularly challenging to detect during normal operation since the overflow may not immediately cause visible system failure, but instead gradually corrupt memory structures that could be exploited later. The exploitation requires careful crafting of input data that aligns with the specific memory layout patterns expected by the vulnerable function, making it a sophisticated attack vector that requires understanding of both the library internals and memory management principles.
The operational impact of CVE-2017-14858 extends far beyond simple denial of service conditions, as it represents a potential gateway for more serious security breaches. Applications that rely on Exiv2 for image metadata processing become vulnerable to attacks that can cause system instability, application crashes, or potentially unauthorized code execution. The vulnerability affects a wide range of software ecosystems including web applications, image processing platforms, and content management systems that utilize Exiv2 for handling image metadata. When exploited, the buffer overflow can cause applications to crash or behave unpredictably, leading to denial of service conditions that can impact legitimate users and potentially be used as part of larger attack campaigns. The vulnerability's impact is amplified by the widespread adoption of Exiv2 across multiple platforms and applications, meaning that a single exploitation can affect numerous systems simultaneously. Organizations using applications that depend on Exiv2 are particularly vulnerable since the library is often integrated into core system functions and user-facing applications. The vulnerability can be exploited through various attack vectors including web uploads, file processing pipelines, and automated image analysis systems. The potential for remote code execution exists in scenarios where the heap corruption can be carefully manipulated to overwrite function pointers or control structures, though this typically requires advanced exploitation techniques. The vulnerability also impacts system availability as legitimate applications may crash or become unresponsive when processing maliciously crafted input files, leading to service disruption and potential business impact.
Mitigation strategies for CVE-2017-14858 should focus on immediate remediation through software updates and comprehensive system hardening measures. The primary and most effective mitigation involves upgrading to Exiv2 version 0.27 or later, where the heap-based buffer overflow has been addressed through proper input validation and memory boundary checks. Organizations should conduct thorough vulnerability assessments to identify all systems and applications that utilize Exiv2, particularly those that process user-uploaded image files or external image data sources. Input validation and sanitization should be implemented at multiple layers, including application-level filtering of image metadata before processing by Exiv2. The implementation of memory safety techniques such as stack canaries, address space layout randomization, and heap integrity checks can provide additional defense-in-depth measures. Regular security monitoring and intrusion detection systems should be configured to identify unusual patterns of image file processing that may indicate exploitation attempts. Network segmentation and access controls should be implemented to limit exposure of systems that process image data, particularly those accessible to untrusted users. Security teams should also consider implementing automated patch management processes to ensure timely deployment of security updates across all affected systems. The vulnerability highlights the importance of maintaining up-to-date third-party libraries and implementing comprehensive software supply chain security practices. Organizations should also establish incident response procedures specifically for handling buffer overflow vulnerabilities and related memory safety issues. Regular security testing including fuzzing and penetration testing of image processing pipelines can help identify similar vulnerabilities in other components of the system architecture. The remediation process should include thorough testing of updated software to ensure that security patches do not introduce regressions or compatibility issues in existing functionality.