From: Michael R Sweet Date: Tue, 26 Jan 2021 08:02:32 -0500 Subject: CVE-2021-23180 Fix a crash bug with malformed URIs (Issue #418) Origin: upstream, https://github.com/michaelrsweet/htmldoc/commit/19c582fb32eac74b57e155cffbb529377a9e751a Bug: https://github.com/michaelrsweet/htmldoc/issues/418 Bug-Debian: https://bugs.debian.org/989437 --- htmldoc/file.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/htmldoc/file.c +++ b/htmldoc/file.c @@ -303,6 +303,7 @@ file_extension(const char *s) /* I - Filename or URL */ { const char *extension; /* Pointer to directory separator */ + char *bufptr; /* Pointer into buffer */ static char buf[1024]; /* Buffer for files with targets */ @@ -326,7 +327,8 @@ strlcpy(buf, extension, sizeof(buf)); - *(char *)strchr(buf, '#') = '\0'; + if ((bufptr = strchr(buf, '#')) != NULL) + *bufptr = '\0'; return (buf); }