Description

An issue in the with_argv function (/unistd/mod.rs) of relibc commit 61f42d allows attackers to cause a Denial of Service (DoS) via a crafted input.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-28T16:17:47.063Z",
  "pubdate": "2026-08-28T16:17:47.063Z",
  "executiveSummary": "A Denial of Service (DoS) vulnerability exists in the with_argv function located within /unistd/mod.rs of the relibc library (commit 61f42d).\nThe vulnerability allows an attacker to terminate the process or induce a crash through the submission of specifically crafted input processed by the with_argv function.\nThis issue impacts the availability of any application linked against the affected version of relibc, as a successful exploit causes an immediate service interruption.\nThe flaw stems from insufficient input validation or error handling within the argument processing logic, which is susceptible to exploitation via malicious environment or argument vectors.\nExploitation does not inherently require high-level administrative privileges, as the impact is localized to the process space of the targeted application.\nThe risk implication is primarily focused on service instability and application failure, posing a significant threat to systems relying on the relibc library for core process execution and management tasks.",
  "technicalDetails": "The vulnerability resides in the with_argv function, which is responsible for managing process arguments and environment variables within the relibc implementation.\nThe root cause of the flaw is an improper handling of memory or input bounds during the parsing or serialization of argv structures.\nWhen an attacker provides a maliciously crafted input, the logic within /unistd/mod.rs fails to correctly validate the length, format, or memory alignment of the input data before processing.\nThe attack flow initiates when a process calls with_argv with externally influenced input, such as manipulated command-line arguments or environment variables.\nThe function enters an undefined state due to the anomalous input, likely triggering an out-of-bounds memory access, a null pointer dereference, or an integer overflow, leading to an immediate process crash (SIGSEGV or SIGABRT).\nBecause the function is designed to handle sensitive process initialization data, the failure occurs at a critical juncture in the process lifecycle, causing the application to terminate before it can perform robust error recovery.\nThe specific commit 61f42d identifies the version affected, suggesting that the logic fails to account for edge cases in argument array termination or memory allocation sizing.\nAn attacker can exploit this by controlling the inputs passed to the function, forcing the runtime to execute instructions on malformed memory segments.\nThe impact of this exploit is limited to the local process context; however, in systems where the affected library is used for handling system-level tasks or privileged processes, the impact could potentially lead to cascading service failures.\nNo complex authentication is required to trigger this vulnerability, as the input processing logic is typically invoked during standard application runtime routines. Success depends entirely on the attacker's ability to influence the arguments or environment variables received by the targeted process."
}