Submit #512803: Open Source libzvbi 0.2.43 Integer Overflow -> Heap Overflow (vbi_search_new)

The function vbi_search_new attempts to find a pattern in a passed string, it takes pat_len which is user controlled as the argument for malloc while performing an arithmetic operation in the call without checking any bounds, ultimately could result in a minimum sized chunk allocation.
if (!regexp) { // user controlled, set to False
if (!(esc_pat = malloc(sizeof(ucs2_t) * pat_len * 2))) { // integer overflow -> under allocation, pat_len is user controlled
free(s);
return NULL;
}

for (i = j = 0; i < pat_len; i++) {
if (strchr("!\"#$%&()*+,-./:;=?@[\\]^_{|}~", pattern[i]))
esc_pat[j++] = '\\';
esc_pat[j++] = pattern[i]; /* effectively can be written to 'everywhere' on the heap starting from esc_pat
*/
}

pattern = esc_pat;
pat_len = j;
}

• User: ninpwn (UID 82253)
• Submission: 03/03/2025 11:22 (1 Year ago)
• Moderation: 03/11/2025 07:06 (8 days later)
• Status: Accepted
• VulDB entry: 299206 [libzvbi up to 0.2.43 src/search.c vbi_search_new pat_len integer overflow]
• Points: 17