Use-after-free vulnerability in libsubcmd
Summary
GSD-2022-1000354: libsubcmd: Fix use-after-free for realloc(..., 0). Affects Kernel versions >= 2f4ce5ec1d447beb42143a9653716a2ab025161e, < aca7e5b6a5008dcf551516490b0ba4510e073d08. No fix is published. How to fix ↓
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Background
The libsubcmd library is a component of the Linux Kernel, which is responsible for providing subcommand handling functionality. It allows programs to define and execute subcommands within a larger command-line interface. The library is widely used in various Linux distributions and applications.
Vulnerability Detail
The use-after-free vulnerability in libsubcmd arises from a flaw in the realloc() function. When realloc() is called with a size of 0, it can lead to a use-after-free condition, where the memory previously allocated is freed but still accessed. This vulnerability can be exploited by an attacker to execute arbitrary code or cause a denial-of-service condition.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
If updating the Linux Kernel is not immediately feasible, a temporary workaround is to avoid calling realloc() with a size of 0. Developers should review their code and ensure that realloc() is used correctly, with a non-zero size parameter.
Conclusion
The use-after-free vulnerability in libsubcmd can be mitigated by updating the Linux Kernel to version v5.4.181 or later. Developers should also review their code to ensure proper usage of realloc(). For further support and assistance in vulnerability remediation, please contact DevNack.com.
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FAQ
Libsubcmd is a library in the Linux Kernel that provides subcommand handling functionality.
A use-after-free vulnerability occurs when a program continues to use memory after it has been freed, leading to potential security issues.
An attacker can exploit this vulnerability by crafting a malicious input that triggers the use-after-free condition, potentially allowing them to execute arbitrary code or cause a denial-of-service.
Yes, this vulnerability has been fixed in the Linux Kernel version v5.4.181 by commit aca7e5b6a5008dcf551516490b0ba4510e073d08.
It is recommended to update the Linux Kernel to the latest version available, which includes the fix for this vulnerability. Alternatively, developers can review their code and ensure that realloc() is used correctly with a non-zero size parameter.
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