CVE-2022-29776 in Document Server
Summary
by MITRE • 06/02/2022
Onlyoffice Document Server v6.0.0 and below and Core 6.1.0.26 and below were discovered to contain a stack overflow via the component DesktopEditor/common/File.cpp.
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Analysis
by VulDB Data Team • 06/06/2022
The vulnerability identified as CVE-2022-29776 represents a critical stack overflow condition affecting Onlyoffice Document Server and Core components version 6.0.0 and below, as well as Core 6.1.0.26 and below. This flaw manifests within the DesktopEditor/common/File.cpp component, which serves as a crucial element in the document processing pipeline of the Onlyoffice suite. The stack overflow vulnerability arises from inadequate input validation and memory management practices within the file handling functionality, creating a potential entry point for malicious actors to exploit the system.
The technical implementation of this vulnerability stems from improper handling of file data structures during the document processing lifecycle. When the DesktopEditor component attempts to process specially crafted or malformed input files, the buffer management mechanisms fail to properly validate the size and content of incoming data. This deficiency allows an attacker to exceed the allocated stack buffer boundaries, leading to memory corruption that can result in arbitrary code execution. The vulnerability operates at the memory management level, specifically targeting the stack-based buffer overflow pattern that has been classified under CWE-121 as "Stack-based Buffer Overflow" and is further categorized under CWE-787 as "Out-of-bounds Write."
From an operational perspective, this vulnerability presents significant risks to organizations utilizing Onlyoffice Document Server and Core services. Attackers could leverage this flaw to execute malicious code on affected systems, potentially leading to complete system compromise, data exfiltration, or lateral movement within network environments. The impact extends beyond individual system compromise as the vulnerability affects document processing capabilities that are fundamental to business operations. Organizations relying on Onlyoffice for collaborative document editing, content management, and enterprise document workflows face potential disruption to their operational continuity and increased exposure to security breaches. The vulnerability's exploitation requires minimal privileges and can be achieved through simple file upload or processing operations, making it particularly dangerous in multi-user environments.
The exploitation of this vulnerability aligns with tactics described in the MITRE ATT&CK framework under the technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1203 for "Exploitation for Client Execution," where attackers can leverage such memory corruption vulnerabilities to gain unauthorized access to systems. Organizations should consider implementing network segmentation, access controls, and monitoring mechanisms to detect potential exploitation attempts. The recommended mitigation strategies include immediate patching of affected versions, implementing input validation controls, and establishing runtime protections such as stack canaries and address space layout randomization. Additionally, organizations should conduct comprehensive vulnerability assessments to identify any potential exploitation attempts and implement network monitoring to detect suspicious file processing activities that may indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper memory management practices and input validation in preventing remote code execution vulnerabilities within document processing applications.