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fix(c): describe the real hazard in insecure-use-strtok-fn #4022

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fix(c): describe the real hazard in insecure-use-strtok-fn #4022

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0299003
fix(c): describe the real hazard in insecure-use-strtok-fn
Eljees Jul 27, 2026
d2e8e14
fix(c): correct state, thread-safety and delimiter wording
Eljees Jul 29, 2026
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9 changes: 6 additions & 3 deletions c/lang/security/insecure-use-strtok-fn.yaml
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Original file line number Diff line number Diff line change
Expand Up @@ -2,9 +2,12 @@ rules:
- id: insecure-use-strtok-fn
pattern: strtok(...)
message: >-
Avoid using 'strtok()'. This function directly modifies the first argument buffer,
permanently erasing the
delimiter character. Use 'strtok_r()' instead.
Avoid 'strtok()': it is not reentrant, and the C standard does not require it to
be thread-safe. It keeps the scan position in hidden static state, so interleaved
calls (even on unrelated strings) clobber each other. It also modifies its input
in place, replacing each token-ending delimiter with a NUL byte. Use the
reentrant 'strtok_r()' (POSIX) or 'strtok_s()' (C11 Annex K), which keep the scan
state in a caller-provided context.
metadata:
cwe:
- 'CWE-676: Use of Potentially Dangerous Function'
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