Alternative functions that limit the number of bytes copied are often recommended to mitigate buffer overflow vulnerabilities. For example:
strncpy() instead of strcpy()strncat() instead of strcat()fgets() instead of gets()snprintf() instead of sprintf()These functions truncate strings that exceed the specified limits. Additionally, some functions such as {{strncpy()}} do not guarantee that the resulting string is null-terminated \[[STR33-C|STR33-C. Guarantee that all strings are null-terminated]\]. |
Truncation results in a loss of data and, in some cases, leads to software vulnerabilities.
An exception to this rule applies if the intent of the programmer was to intentionally truncate the null-terminated byte string. To be compliant with this standard, this intent must be clearly stated in comments.
Rule |
Severity |
Likelihood |
Remediation Cost |
Priority |
Level |
|---|---|---|---|---|---|
STR34-C |
1 (low) |
1 (unlikely) |
2 (medium) |
P2 |
L3 |