PT-2020-6049 · Exim+5 · Exim+5

Published 2020-10-20 · Updated 2024-06-15 · CVE-2020-28007

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Exim versions prior to 4.94.2

Description The issue is related to the Exim message transfer agent and involves a problem with symbolic link tracking. An attacker can exploit this by creating a specially crafted symbolic link to a file and overwriting it with application privileges, potentially allowing privilege escalation in the system. This can be achieved because Exim operates as root in the log directory, which is owned by a non-root user, making it vulnerable to symlink or hard link attacks that can overwrite critical root-owned files anywhere on the filesystem.

Recommendations For Exim versions prior to 4.94.2, update to version 4.94.2 or later to resolve the issue. As a temporary workaround, consider restricting access to the log directory to minimize the risk of exploitation.

Exploit

Fix

Link Following

Weakness Enumeration

CWE-59

CWE-264

CWE-61

Related Identifiers

ALT-PU-2021-1764

ALT-PU-2022-2269

BDU:2021-02750

BDU:2021-02768

CVE-2020-28007

DLA-2650-1

DSA-4912-1

OPENSUSE-SU-2021:0677-1

OPENSUSE-SU-2021:0753-1

OPENSUSE-SU-2021:0754-1

OPENSUSE-SU-2021_0677-1

OPENSUSE-SU-2024:10746-1

USN-4934-1

USN-4934-2

Affected Products

Alt Linux

Astra Linux

Exim

Linuxmint

Suse

Ubuntu

References · 109

• 🔥 https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/exim4_deliver_message_priv_esc.rb · Exploit
• 🔥 https://github.com/qazbnm456/awesome-cve-poc/blob/master/Stack-Clash.md · Exploit
• 🔥 https://github.com/synacktiv/Exim-CVE-2019-15846 · Exploit
• 🔥 https://github.com/LetUsFsck/PoC-Exploit-Mirror/tree/master/CVE-2017-16944 · Exploit
• 🔥 https://github.com/Diefunction/CVE-2019-10149 · Exploit
• 🔥 https://github.com/cowbe0x004/eximrce-CVE-2019-10149 · Exploit
• 🔥 https://github.com/MNEMO-CERT/PoC--CVE-2019-10149_Exim · Exploit
• 🔥 https://github.com/martinclauss/exim-rce-cve-2018-6789 · Exploit
• 🔥 https://github.com/synacktiv/Exim-CVE-2018-6789 · Exploit
• 🔥 https://github.com/AzizMea/CVE-2019-10149-privilege-escalation · Exploit
• 🔥 https://github.com/darsigovrustam/CVE-2019-10149 · Exploit
• 🔥 https://github.com/dorkerdevil/CVE-2020-28018 · Exploit
• 🔥 https://github.com/cloudflare/exim-cve-2019-10149-data · Exploit
• 🔥❌ https://github.com/lmol/CVE-2020-28018 · Exploit, Deleted
• https://osv.dev/vulnerability/openSUSE-SU-2021:0754-1 · Vendor Advisory