Exim 4 before 4.94.2 allows Execution with Unnecessary Privileges. Because Exim operates as root in the spool directory (owned by a non-root user), an attacker can write to a /var/spool/exim4/input spool header file, in which a crafted recipient address can indirectly lead to command execution.
Weakness
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Exim | Exim | 4.00 (including) | 4.94.2 (excluding) |
| Exim4 | Ubuntu | bionic | * |
| Exim4 | Ubuntu | devel | * |
| Exim4 | Ubuntu | esm-infra-legacy/trusty | * |
| Exim4 | Ubuntu | esm-infra/bionic | * |
| Exim4 | Ubuntu | esm-infra/focal | * |
| Exim4 | Ubuntu | esm-infra/xenial | * |
| Exim4 | Ubuntu | focal | * |
| Exim4 | Ubuntu | groovy | * |
| Exim4 | Ubuntu | hirsute | * |
| Exim4 | Ubuntu | impish | * |
| Exim4 | Ubuntu | jammy | * |
| Exim4 | Ubuntu | trusty | * |
| Exim4 | Ubuntu | trusty/esm | * |
| Exim4 | Ubuntu | xenial | * |
Potential Mitigations
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/122.html
- https://cwe.mitre.org/data/definitions/233.html
- https://cwe.mitre.org/data/definitions/58.html