Fedora 27 update for exim

Published: 2017-12-01 | Updated: 2025-04-24

Risk	High
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2017-16944 CVE-2017-16943
CWE-ID	CWE-835 CWE-416
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	Fedora Operating systems & Components / Operating system exim Operating systems & Components / Operating system package or component
Vendor	Fedoraproject

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Infinite loop

EUVDB-ID: #VU9428

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 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

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

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 27

exim: before 4.89-7.fc27

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2017-0053bb9719

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.

2) Use-after-free error

EUVDB-ID: #VU9427

Risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2017-16943

CWE-ID: CWE-416 - Use After Free