CVE-2017-7882 in LibreOffice
Summary
by MITRE
LibreOffice before 2017-03-14 has an out-of-bounds write related to the HWPFile::TagsRead function in hwpfilter/source/hwpfile.cxx.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7882 represents a critical out-of-bounds write flaw within LibreOffice's HWP file filter component. This issue affects versions prior to the 2017-03-14 release and specifically targets the HWPFile::TagsRead function located in the hwpfilter/source/hwpfile.cxx source file. The vulnerability arises when processing HWP (Hangul Word Processor) files, which are document formats native to Korean word processing software. The flaw occurs during the parsing of HWP file structures where the application fails to properly validate array bounds before writing data to memory locations.
The technical nature of this vulnerability places it squarely within the CWE-787 category of out-of-bounds write conditions, which represents a fundamental memory safety issue that can lead to arbitrary code execution. When an attacker crafts a malicious HWP file with malformed data structures, the HWPFile::TagsRead function attempts to write data beyond the allocated memory boundaries, potentially overwriting adjacent memory regions. This type of vulnerability is particularly dangerous in office productivity applications like LibreOffice since they frequently process untrusted document files from various sources. The out-of-bounds write can result in application crashes, memory corruption, or more severely, provide attackers with opportunities to execute malicious code through memory corruption exploits.
The operational impact of CVE-2017-7882 extends beyond simple application instability to encompass potential system compromise. Attackers could leverage this vulnerability by delivering malicious HWP files through phishing campaigns, file sharing platforms, or compromised websites where users might unknowingly open documents. When a user opens such a crafted file within LibreOffice, the application's memory corruption could lead to privilege escalation or complete system compromise depending on the execution environment. The vulnerability's exploitation aligns with attack patterns documented in the MITRE ATT&CK framework under the technique of code injection and memory corruption attacks. This flaw particularly affects users in environments where LibreOffice serves as the primary document processing tool for Korean language content, making it a significant concern for organizations with international document processing requirements.
Mitigation strategies for CVE-2017-7882 primarily focus on immediate patching of affected LibreOffice installations to version 5.3.3 or later, which includes the necessary fixes for the HWP file parsing routine. System administrators should implement comprehensive software update policies to ensure all users have access to the latest security patches. Additionally, organizations can deploy application whitelisting solutions to restrict execution of untrusted document files and implement sandboxing techniques for document processing. Network-based security controls such as email filtering and web proxies can help prevent delivery of malicious HWP files through common attack vectors. The vulnerability underscores the importance of regular security assessments and vulnerability management programs, particularly for office productivity suites that handle diverse document formats. Organizations should also consider implementing file format validation and content inspection mechanisms to detect and prevent exploitation attempts. Security monitoring should include detection of unusual memory access patterns and application crashes that might indicate exploitation attempts targeting similar memory corruption vulnerabilities in office applications.