systemd 250 and 251 allows local users to achieve a systemd-coredump deadlock by triggering a crash that has a long backtrace. This occurs in parse_elf_object in shared/elf-util.c. The exploitation methodology is to crash a binary calling the same function recursively, and put it in a deeply nested directory to make its backtrace large enough to cause the deadlock. This must be done 16 times when MaxConnections=16 is set for the systemd/units/systemd-coredump.socket file.
systemd 250 y 251 permiten a los usuarios locales lograr un punto muerto en systemd-coredump al desencadenar un bloqueo que tiene un largo backtrace. Esto ocurre en parse_elf_object enshared/elf-util.c. La metodología de explotación consiste en bloquear un binario que llama a la misma función de forma recursiva y colocarlo en un directorio profundamente anidado para que su seguimiento sea lo suficientemente grande como para provocar el punto muerto. Esto se debe hacer 16 veces cuando se establece MaxConnections=16 para el archivo systemd/units/systemd-coredump.socket.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-400
|
| 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary |
en
CWE-400
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| systemd_project | systemd | * | <built-in method update of dict object at 0x7fd340892cc0> | Application |
| systemd_project | systemd | 252 | <built-in method update of dict object at 0x7fd340891680> | Application |
| systemd_project | systemd | 252 | <built-in method update of dict object at 0x7fd3854bfb00> | Application |
| fedoraproject | fedora | 36 | <built-in method update of dict object at 0x7fd341be8840> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:a:systemd_project:systemd:252:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:a:systemd_project:systemd:252:rc2:*:*:*:*:*:* |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* |