CVE-2018-7730 in Exempi
Summary
by MITRE
An issue was discovered in Exempi through 2.4.4. A certain case of a 0xffffffff length is mishandled in XMPFiles/source/FormatSupport/PSIR_FileWriter.cpp, leading to a heap-based buffer over-read in the PSD_MetaHandler::CacheFileData() function.
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Analysis
by VulDB Data Team • 02/17/2023
The vulnerability identified as CVE-2018-7730 represents a critical heap-based buffer over-read flaw within the Exempi library version 2.4.4 and earlier. This issue manifests specifically in the XMPFiles component when processing certain malformed PSD files, creating a scenario where the application fails to properly validate input data length parameters. The flaw exists within the PSIR_FileWriter.cpp source file where a particular case handling a 0xffffffff length value results in improper memory management during file processing operations.
The technical implementation of this vulnerability stems from inadequate bounds checking within the PSD_MetaHandler::CacheFileData() function. When the system encounters a 0xffffffff length value, the memory allocation logic fails to properly validate the input parameter, causing the application to attempt reading beyond the allocated heap buffer boundaries. This over-read condition allows an attacker to potentially access uninitialized memory regions or extract sensitive information from adjacent memory locations. The vulnerability falls under CWE-125, which specifically addresses out-of-bounds read conditions in software implementations, making it particularly dangerous in security-sensitive applications that process untrusted file inputs.
The operational impact of this vulnerability extends beyond simple data corruption, as it creates potential attack vectors for information disclosure and remote code execution scenarios. When exploited, this buffer over-read could enable adversaries to extract memory contents that may contain sensitive data such as cryptographic keys, user credentials, or application state information. The flaw particularly affects applications that rely on Exempi for XMP metadata processing, including digital asset management systems, photo editing software, and content management platforms that handle PSD files from untrusted sources. This vulnerability aligns with ATT&CK technique T1059, specifically targeting application security flaws through file processing exploits.
Mitigation strategies for CVE-2018-7730 require immediate implementation of version updates to Exempi 2.4.5 or later, which contain the necessary patches addressing the buffer over-read condition. Organizations should also implement input validation measures that strictly enforce length parameters and implement robust memory management practices within their applications. Additional protective measures include deploying web application firewalls that can detect and block malformed PSD file requests, implementing sandboxing techniques for file processing operations, and conducting regular security audits of third-party libraries. System administrators should monitor for any exploitation attempts through network traffic analysis and implement proper access controls to limit exposure of vulnerable applications to untrusted file inputs. The patching process should be prioritized at the highest level due to the potential for remote code execution and information disclosure vulnerabilities that this flaw presents to affected systems.