CVE-2020-1931
Description
From CVE.org
A command execution issue was found in Apache SpamAssassin prior to 3.4.3. Carefully crafted nefarious Configuration (.cf) files can be configured to run system commands similar to CVE-2018-11805. This issue is less stealthy and attempts to exploit the issue will throw warnings. Thanks to Damian Lukowski at credativ for reporting the issue ethically. With this bug unpatched, exploits can be injected in a number of scenarios though doing so remotely is difficult. In addition to upgrading to SA 3.4.4, we again recommend that users should only use update channels or 3rd party .cf files from trusted places.
Statement
The attack is triggered by malicious specially crafted .cf files which are basically configuration files for spamassasin. These files can be located at:
- /usr/share/spamassassin
- /etc/mail/spamassassin
- user's home directory, in a directory called .spamassassin
All of these locations can only be accessed by either the system administrator or by a user having a local shell account on the machine. In order to successfully exploit this flaw, the attacker needs to convince the user to place the malicious configuration files in one of the above locations.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.7 | 8.1 | N/A |
| Attack Vector | Local | Network | N/A |
| Attack Complexity | Low | High | N/A |
| Privileges Required | High | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
The location for spamassassin configuration files is local and requires high privileges to access, which explains the core differences.
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Non-Repudiation
Technical Impact: Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart; Read Files or Directories; Modify Files or Directories; Read Application Data; Modify Application Data; Hide Activities
Attackers could execute unauthorized operating system commands, which could then be used to disable the product, or read and modify data for which the attacker does not have permissions to access directly. Since the targeted application is directly executing the commands instead of the attacker, any malicious activities may appear to come from the application or the application's owner.
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