Multiple vulnerabilities in Exim
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 2 |
| CVE-ID | CVE-2022-37452 CVE-2021-38371 |
| CWE-ID | CWE-122 CWE-300 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
Exim Server applications / Mail servers |
| Vendor | Exim |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
1) Heap-based buffer overflow
EUVDB-ID: #VU66691
Risk: High
CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2022-37452
CWE-ID:
CWE-122 - Heap-based Buffer Overflow
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error for the alias list within the host_name_lookup() function in host.c when the sender_host_name is set. A remote attacker can initiate a connection to the affected server, trigger a heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall update from vendor's website.
Vulnerable software versionsExim: 4.00 - 4.94.2
External linkshttp://www.exim.org/static/doc/security/
http://github.com/ivd38/exim_overflow
http://www.openwall.com/lists/oss-security/2022/08/06/8
http://github.com/Exim/exim/commit/d4bc023436e4cce7c23c5f8bb5199e178b4cc743
http://github.com/Exim/exim/wiki/EximSecurity
http://github.com/Exim/exim/compare/exim-4.94...exim-4.95
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Man-in-the-Middle (MitM) attack
EUVDB-ID: #VU73857
Risk: Medium
CVSSv3.1: 6.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-38371
CWE-ID:
CWE-300 - Channel Accessible by Non-Endpoint ('Man-in-the-Middle')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists due to the way Exim handles concurrent STARTTLS sessions when sending out emails. A malicious server can send a response to the *next* command within the existing STARTTLS sessions and force the Exim to treat this session as trusted.
Install updates from vendor's website.
Vulnerable software versionsExim: 4.00 - 4.94.2
External linkshttp://www.exim.org
http://nostarttls.secvuln.info
http://www.exim.org/static/doc/security/CVE-2021-38371.txt
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
