提出 #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;
}

• ユーザー: ninpwn (UID 82253)
• 送信: 2025年03月03日 11:22 (1 年 ago)
• モデレーション: 2025年03月11日 07:06 (8 days later)
• ステータス: 承諾済み
• VulDBエントリ: 299206 [libzvbi 迄 0.2.43 src/search.c vbi_search_new pat_len メモリ破損]
• ポイント: 17