A use-after-free vulnerability was found in systemd. This issue occurs due to the on_stream_io() function and dns_stream_complete() function in resolved-dns-stream.c not incrementing the reference counting for the DnsStream object. Therefore, other functions and callbacks called can dereference the DNSStream object, causing the use-after-free when the reference is still used later.
Weakness
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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Systemd | Systemd_project | 240 (including) | 240 (including) |
| Red Hat Enterprise Linux 7 | RedHat | systemd-0:219-78.el7_9.7 | * |
| Red Hat Enterprise Linux 8 | RedHat | systemd-0:239-58.el8_6.4 | * |
| Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions | RedHat | systemd-0:239-18.el8_1.11 | * |
| Red Hat Enterprise Linux 8.2 Extended Update Support | RedHat | systemd-0:239-31.el8_2.9 | * |
| Red Hat Enterprise Linux 8.4 Extended Update Support | RedHat | systemd-0:239-45.el8_4.12 | * |
| Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 | RedHat | redhat-virtualization-host-0:4.5.2-202209140405_8.6 | * |
| Systemd | Ubuntu | bionic | * |
| Systemd | Ubuntu | esm-infra/bionic | * |
| Systemd | Ubuntu | trusty | * |
| Systemd | Ubuntu | upstream | * |
| Systemd | Ubuntu | xenial | * |