Tristan

The regcomp and regexec functions in the GNU C Library version 2.3 to version 2.44 may read freed memory and free the same heap block twice when a memory allocation fails while a regular expression is compiled or matched. The re dfa add node (the NFA node table) and build range exp (bracket ranges) grow several arrays with consecutive realloc calls and store the new pointers only after all of them succeed. When a later call fails, the pattern buffer keeps pointers to blocks that were already freed, and the error cleanup frees them again. In regexec, the back-reference cache (match ctx add entry) frees its array when a realloc fails but keeps the pointer, which is freed again on the error path. An attacker does not need to supply a crafted regular expression: patterns large enough to grow these arrays are common. The failure has to hit a specific allocation, though, so the issue can only be reached when the system is already under memory pressure. An attacker who supplies the pattern or the subject string has little control over which allocation fails, so the expected impact is a crash of the process. This issue affects all architectures and ABIs supported by the GNU C Library.

The RAOP module accepts unbounded Content-Length values and fails to verify the return value of the `pw array add()` function. This lack of validation can lead to memory management issues when processing incoming requests.

The PulseAudio protocol server contains multiple unbounded `alloca()` calls. The `alloca()` function allocates memory on the stack, and when these calls are unbounded, they can lead to stack exhaustion.

The issue is an unauthenticated Cross-Site Scripting vulnerability. Any web service hosted on the same subdomain can set a cookie for the whole subdomain, which can be used to bypass other mitigations in place for malicious purposes.