#VU9428 Infinite loop in Exim - CVE-2017-16944

Vulnerability identifier: #VU9428

Vulnerability risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-16944

CWE-ID: CWE-835

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Exim
Server applications / Mail servers

Vendor: Exim

Description
The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists due to infinite loop in bdat_getc(). A remote attacker can connect to the SMTP service, send a specially crafted BDAT command, consume all available stack memory and cause the service to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation
Update to version 4.90.

Vulnerable software versions

Exim: 4.88 - 4.89

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External links
https://git.exim.org/exim.git/commit/4e6ae6235c68de243b1c2419027472d7659aa2b4

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.