A heap use-after-free vulnerability was found in systemd before version v245-rc1, where asynchronous Polkit queries are performed while handling dbus messages. A local unprivileged attacker can abuse this flaw to crash systemd services or potentially execute code and elevate their privileges, by sending specially crafted dbus messages.
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1712 | patch issue tracking third party advisory |
| https://www.openwall.com/lists/oss-security/2020/02/05/1 | patch third party advisory mailing list |
| https://github.com/systemd/systemd/commit/ea0d0ede03c6f18dbc5036c5e9cccf97e415ccc2 | patch third party advisory |
| https://github.com/systemd/systemd/commit/1068447e6954dc6ce52f099ed174c442cb89ed54 | patch third party advisory |
| https://github.com/systemd/systemd/commit/637486261528e8aa3da9f26a4487dc254f4b7abb | patch third party advisory |
| https://github.com/systemd/systemd/commit/bc130b6858327b382b07b3985cf48e2aa9016b2d | patch third party advisory |
| https://lists.debian.org/debian-lts-announce/2022/06/msg00025.html | third party advisory mailing list |