A use after free vulnerability exists in curl <7.87.0. Curl can be asked to *tunnel* virtually all protocols it supports through an HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations. When getting denied to tunnel the specific protocols SMB or TELNET, curl would use a heap-allocated struct after it had been freed, in its transfer shutdown code path.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://hackerone.com/reports/1764858 | issue tracking exploit third party advisory |
| https://security.netapp.com/advisory/ntap-20230214-0002/ | vendor advisory |
| https://support.apple.com/kb/HT213670 | third party advisory |
| http://seclists.org/fulldisclosure/2023/Mar/17 | third party advisory mailing list |
| https://security.gentoo.org/glsa/202310-12 | third party advisory vendor advisory |