Infinite loop in Exim - CVE-2017-16944

 

Infinite loop in Exim - CVE-2017-16944

Published: November 28, 2017 / Updated: February 5, 2018


Vulnerability identifier: #VU9428
CSH Severity: Low
CVSS v4: 6.9 [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]
CVE-ID: CVE-2017-16944
CWE-ID: CWE-835
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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.

Affected software

Exim
Arch Linux
Debian Linux
Amazon Linux AMI
Gentoo Linux
Fedora
Ubuntu
exim (Alpine package)
exim

How to mitigate CVE-2017-16944

Update to version 4.90.

exim (Alpine package) - update to 4.89.1-r0
exim - addressed in versions 4.89-4.el6, 4.89-4.el7, 4.89-7.fc26, 4.89-7.fc27

External References

Related Security Bulletins