CVE-2022-1621 in vim
Summary
by MITRE • 05/10/2022
Heap buffer overflow in vim_strncpy find_word in GitHub repository vim/vim prior to 8.2.4919. This vulnerability is capable of crashing software, Bypass Protection Mechanism, Modify Memory, and possible remote execution
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Analysis
by VulDB Data Team • 04/09/2026
The heap buffer overflow vulnerability identified as CVE-2022-1621 resides within the vim text editor's vim_strncpy function in the find_word implementation within the GitHub repository vim/vim. This flaw affects versions prior to 8.2.4919 and represents a critical security issue that can lead to arbitrary code execution under specific conditions. The vulnerability manifests when the application processes input strings without proper bounds checking, allowing attackers to write beyond allocated memory boundaries in the heap allocation space.
The technical flaw stems from insufficient validation of string length parameters during memory copying operations within the vim_strncpy function. When processing word boundaries in text files, the find_word routine fails to properly validate input lengths before copying data to heap-allocated buffers. This condition creates a scenario where malicious input can cause a buffer overflow, potentially leading to memory corruption that may be exploited by adversaries. The vulnerability specifically targets heap-based memory management, making it particularly dangerous as it can be leveraged to manipulate heap metadata and potentially execute arbitrary code through controlled memory corruption.
The operational impact of CVE-2022-1621 extends beyond simple application crashes to encompass serious security implications including bypass protection mechanisms and memory modification capabilities. When exploited successfully, this vulnerability can enable remote code execution, allowing attackers to gain unauthorized access to systems running vulnerable versions of vim. The heap-based nature of the overflow means that attackers can manipulate heap metadata structures, potentially leading to privilege escalation or complete system compromise depending on the execution context. The vulnerability affects both local and remote exploitation scenarios, making it particularly concerning for environments where vim is used with untrusted input sources.
Mitigation strategies for CVE-2022-1621 primarily focus on immediate version updates to vim 8.2.4919 or later, which contain the necessary patches to address the heap buffer overflow conditions. Organizations should implement comprehensive patch management procedures to ensure all instances of vim are updated promptly, particularly in environments where the editor processes untrusted input. Additional protective measures include implementing strict input validation protocols, deploying heap protection mechanisms such as stack canaries and address space layout randomization, and monitoring for suspicious memory access patterns. Security teams should also consider implementing application whitelisting policies that restrict vim execution to trusted environments and monitor for potential exploitation attempts through network-based detection systems.
This vulnerability aligns with CWE-121 heap-based buffer overflow classification and maps to ATT&CK technique T1059.007 for command and script injection, as successful exploitation could enable attackers to execute arbitrary commands through the vulnerable vim process. The vulnerability demonstrates the critical importance of proper memory management in text processing applications and highlights the need for comprehensive security testing of string manipulation functions in widely deployed software components. Organizations should conduct thorough vulnerability assessments to identify other potential buffer overflow conditions in similar text processing applications and ensure that input validation mechanisms are robust against malformed data inputs.