CVE-2020-28007

Ubuntu Security Notice USN-4934-1

Severity Score

7.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Exim 4 before 4.94.2 allows Execution with Unnecessary Privileges. Because Exim operates as root in the log directory (owned by a non-root user), a symlink or hard link attack allows overwriting critical root-owned files anywhere on the filesystem.

Exim 4 versiones anteriores a 4.94.2, permite una Ejecución con Privilegios Innecesarios. Debido a que Exim opera como root en el directorio de registro (propiedad para un usuario no root), un ataque de enlace simbólico o físico permite sobrescribir archivos críticos de propiedad root en cualquier parte del sistema de archivos

USN-4934-1 fixed several vulnerabilities in Exim. This update provides the corresponding update for Ubuntu 14.04 ESM and Ubuntu 16.04 ESM. CVE-2020-28026 only affected Ubuntu 16.04 ESM. It was discovered that Exim contained multiple security issues. An attacker could use these issues to cause a denial of service, execute arbitrary code remotely, obtain sensitive information, or escalate local privileges. Various other issues were also addressed.

*Credits: N/A

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-10-30 CVE Reserved
2021-05-04 CVE Published
2024-08-04 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-59: Improper Link Resolution Before File Access ('Link Following')

CAPEC

References (1)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28007-LFDIR.txt	2021-05-10

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Exim Search vendor "Exim"		Exim Search vendor "Exim" for product "Exim"				>= 4.00 < 4.94.2 Search vendor "Exim" for product "Exim" and version " >= 4.00 < 4.94.2"		-		Affected