CVE-2007-2645 in libexif
Summary
by MITRE
Integer overflow in the exif_data_load_data_entry function in exif-data.c in libexif before 0.6.14 allows user-assisted remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via crafted EXIF data, involving the (1) doff or (2) s variable.
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Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2007-2645 represents a critical integer overflow flaw within the libexif library version 0.6.13 and earlier, which serves as a foundational component for handling exchangeable image file format data in numerous image processing applications. This vulnerability specifically affects the exif_data_load_data_entry function located in the exif-data.c source file, where improper handling of integer values creates conditions that can be exploited by malicious actors to manipulate program execution flow.
The technical implementation of this vulnerability stems from inadequate bounds checking when processing EXIF metadata structures, particularly in how the function handles two specific variables identified as doff and s. When crafted EXIF data contains maliciously constructed values for these variables, the integer overflow occurs during arithmetic operations, leading to unpredictable memory state modifications and potential control flow redirection. This flaw operates under the Common Weakness Enumeration category CWE-190, which classifies integer overflow conditions that can result in memory corruption and arbitrary code execution.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can potentially enable remote code execution when exploited by attackers who craft malicious EXIF data for image files. Systems that process or display EXIF metadata from untrusted sources become vulnerable to this attack vector, particularly affecting applications such as web browsers, image viewers, content management systems, and any software that relies on libexif for metadata handling. The vulnerability is particularly dangerous because it can be triggered through user-assisted remote exploitation, meaning that simply viewing an image file containing malicious EXIF data could cause system compromise.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1203, which involves the use of execution through system binaries, as the overflow can potentially lead to arbitrary code execution within the context of the vulnerable application. The exploitability of this flaw increases significantly in environments where users can upload or view images from untrusted sources, such as web applications, social media platforms, or email clients that automatically process image attachments. Organizations using affected software versions face substantial risk of system compromise, data loss, or service disruption when this vulnerability is successfully exploited.
Mitigation strategies for CVE-2007-2645 primarily involve immediate upgrade to libexif version 0.6.14 or later, which contains the necessary patches to address the integer overflow conditions. Additionally, implementing input validation measures that sanitize EXIF metadata before processing can provide defense-in-depth protection, while network segmentation and access controls can limit the potential impact of successful exploitation attempts. Security monitoring should focus on detecting unusual image processing activities or memory corruption patterns that may indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper integer handling and bounds checking in security-sensitive code, particularly within libraries that process untrusted data from external sources.