Risk | High |
Patch available | YES |
Number of vulnerabilities | 1 |
CVE-ID | CVE-2017-16943 |
CWE-ID | CWE-416 |
Exploitation vector | Network |
Public exploit | N/A |
Vulnerable software Subscribe |
Exim Server applications / Mail servers |
Vendor | Exim |
Security Bulletin
This security bulletin contains one high risk vulnerability.
EUVDB-ID: #VU9427
Risk: High
CVSSv3.1: 8.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2017-16943
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The weakness exists due to a use-after-free memory error in the ESMTP CHUNKING extension within the receive_msg() function in receive.c. A remote attacker can connect to the SMTP service, send a specially crafted BDAT command, trigger memory corruption and execute arbitrary code on the target system.
Successful exploitation of the vulnerability may result in system compromise.
Update to version 4.90.
The vendor has described a workaround:
".. in the main section of your Exim configuration, set:
chunking_advertise_hosts =
This disables advertising the ESMTP CHUNKING extension, making the BDAT verb unavailable and avoids letting an attacker apply the logic."
Exim: 4.88 - 4.89
External linkshttp://git.exim.org/exim.git/commitdiff/4e6ae6235c68de243b1c2419027472d7659aa2b4
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.