[PR #1801] fix(smptett): replace unsafe string operations with bounds-checked versions #2540

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claunia · 2026-01-29T17:22:41Z

claunia commented

2026-01-29 17:22:41 +00:00

Original Pull Request: https://github.com/CCExtractor/ccextractor/pull/1801

State: closed
Merged: Yes

Summary

Replace all sprintf, strcpy, and strcat calls with bounds-checked versions
Add NULL checks after malloc allocations
Prevent potential buffer overflows in SMPTE Timed Text encoder

Changes

Function	Change
`write_stringz_as_smptett`	Use `snprintf` with `sizeof(str)` for timestamp formatting
`write_cc_bitmap_as_smptett`	Use `snprintf` with `INITIAL_ENC_BUFFER_CAPACITY`
`write_cc_buffer_as_smptett`	Major rewrite:
	- Add NULL checks for `final` and `temp` malloc
	- Track `buf_size` and use throughout
	- Replace `strcpy/strcat` chains with `memcpy/snprintf`
	- Use `snprintf` for style tags and color code formatting

Test plan

Build succeeds without errors
Verify SMPTE-TT output format is unchanged for basic subtitles
Verify styled subtitles (italic, bold, underline) render correctly
Verify font color subtitles render correctly

🤖 Generated with Claude Code

**Original Pull Request:** https://github.com/CCExtractor/ccextractor/pull/1801 **State:** closed **Merged:** Yes --- ## Summary - Replace all `sprintf`, `strcpy`, and `strcat` calls with bounds-checked versions - Add NULL checks after malloc allocations - Prevent potential buffer overflows in SMPTE Timed Text encoder ## Changes | Function | Change | |----------|--------| | `write_stringz_as_smptett` | Use `snprintf` with `sizeof(str)` for timestamp formatting | | `write_cc_bitmap_as_smptett` | Use `snprintf` with `INITIAL_ENC_BUFFER_CAPACITY` | | `write_cc_buffer_as_smptett` | Major rewrite: | | | - Add NULL checks for `final` and `temp` malloc | | | - Track `buf_size` and use throughout | | | - Replace `strcpy/strcat` chains with `memcpy/snprintf` | | | - Use `snprintf` for style tags and color code formatting | ## Test plan - [x] Build succeeds without errors - [ ] Verify SMPTE-TT output format is unchanged for basic subtitles - [ ] Verify styled subtitles (italic, bold, underline) render correctly - [ ] Verify font color subtitles render correctly 🤖 Generated with [Claude Code](https://claude.com/claude-code)

claunia added the pull-request label 2026-01-29 17:22:41 +00:00

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Reference: starred/ccextractor#2540