CVE-2022-1908 in libmobi
Summary
by MITRE • 05/27/2022
Buffer Over-read in GitHub repository bfabiszewski/libmobi prior to 0.11.
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Analysis
by VulDB Data Team • 07/19/2025
The vulnerability CVE-2022-1908 represents a critical buffer over-read issue discovered in the libmobi library version prior to 011. This library serves as a core component for processing mobi file format documents, which are commonly used for e-books and digital publishing. The buffer over-read vulnerability occurs when the library processes malformed or specially crafted mobi files that contain excessive data in specific fields, causing the application to read memory beyond the allocated buffer boundaries. This flaw exists within the parsing logic that handles various metadata and content structures within mobi documents, specifically affecting how the library manages memory allocation for string and binary data fields during document processing. The vulnerability was identified in the library's handling of document headers and internal data structures, where insufficient bounds checking allows attackers to manipulate memory access patterns through crafted input files.
The technical implementation of this vulnerability stems from inadequate input validation and memory management within the libmobi parsing functions. When processing mobi documents, the library allocates fixed-size buffers for various data elements but fails to properly verify that incoming data fits within these boundaries before copying or processing. This over-read condition manifests when the parser encounters specially constructed mobi files where field lengths are set to values exceeding the allocated buffer size, causing the application to access adjacent memory locations. The flaw can be categorized under CWE-125 as an out-of-bounds read, which is a common vulnerability pattern in memory safety issues. The vulnerability's impact is amplified by the widespread use of libmobi in various applications and systems that handle mobi document formats, including e-book readers, digital publishing platforms, and content management systems.
The operational impact of CVE-2022-1908 extends beyond simple memory corruption, as it can potentially enable arbitrary code execution or information disclosure depending on the system environment and how the library is integrated. Attackers can exploit this vulnerability by creating malicious mobi files that trigger the buffer over-read condition when processed by applications using vulnerable versions of libmobi. The attack vector typically involves social engineering to deliver crafted mobi files to unsuspecting users, or through automated systems that process documents from untrusted sources. This vulnerability aligns with ATT&CK technique T1203 as a form of input manipulation that leads to memory corruption. The potential for remote code execution increases significantly when the vulnerable library is used in web applications or services that process user-uploaded documents, making it particularly dangerous in environments where untrusted content is regularly handled. Organizations using applications that depend on libmobi are at risk of system compromise, data leakage, or service disruption.
Mitigation strategies for CVE-2022-1908 primarily focus on updating to the patched version 0.11 or later of libmobi, which includes proper bounds checking and memory validation mechanisms. System administrators should conduct comprehensive vulnerability assessments to identify all applications and services that utilize the vulnerable library, ensuring complete remediation across the entire application ecosystem. Additional protective measures include implementing strict input validation for all mobi document processing, deploying network segmentation to limit exposure, and monitoring for suspicious document processing activities. Security teams should also consider implementing application whitelisting policies that restrict the execution of untrusted mobi files, along with regular security testing of document processing pipelines. The fix implemented in version 0.11 addresses the root cause by introducing proper bounds checking in all memory allocation and data processing functions, ensuring that buffer sizes are verified before data is copied or accessed. Organizations should also establish processes for continuous monitoring of third-party library vulnerabilities and maintain up-to-date security patches for all components in their software supply chain, as demonstrated by the importance of addressing vulnerabilities in widely-used libraries like libmobi that serve as foundational components for numerous applications.