CVE-2017-16944 : The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to cause a denial

The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to cause a denial of service (infinite loop and stack exhaustion) via vectors involving BDAT commands and an improper check for a '.' character signifying the end of the content, related to the bdat_getc function.

Published 2017-11-25 17:29:00

Updated 2021-05-04 18:15:08

Source MITRE

View at NVD, CVE.org

Vulnerability category: Denial of service

Threat overview for CVE-2017-16944

Top countries where our scanners detected CVE-2017-16944

Top open port discovered on systems with this issue 80

IPs affected by CVE-2017-16944 7,937

Threat actors abusing to this issue? Yes

Find out if you^* are affected by CVE-2017-16944!

^*Directly or indirectly through your vendors, service providers and 3rd parties. Powered by attack surface intelligence from SecurityScorecard.

Exploit prediction scoring system (EPSS) score for CVE-2017-16944

Probability of exploitation activity in the next 30 days: 85.06%

Percentile, the proportion of vulnerabilities that are scored at or less: ~ 98 % EPSS Score History EPSS FAQ

CVSS scores for CVE-2017-16944

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
5.0	MEDIUM	AV:N/AC:L/Au:N/C:N/I:N/A:P	10.0	2.9	NIST
Access Vector: Network Access Complexity: Low Authentication: None Confidentiality Impact: None Integrity Impact: None Availability Impact: Partial
7.5	HIGH	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	3.9	3.6	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: None Availability: High

CWE ids for CVE-2017-16944

CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')

The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

Assigned by: nvd@nist.gov (Primary)

References for CVE-2017-16944

https://lists.exim.org/lurker/message/20171125.034842.d1d75cac.en.html

[exim-announce] Critical Exim Security Vulnerability: disable chunking
Mailing List

CVEs referencing this url
http://openwall.com/lists/oss-security/2017/11/25/3

oss-security - Re: RCE in Exim reported
Mailing List

CVEs referencing this url
http://openwall.com/lists/oss-security/2017/11/25/2

oss-security - RCE in Exim reported
Mailing List

CVEs referencing this url
https://www.exploit-db.com/exploits/43184/

Exim 4.89 - 'BDAT' Denial of Service
Third Party Advisory;VDB Entry
http://www.openwall.com/lists/oss-security/2021/05/04/7

oss-security - 21Nails: Multiple vulnerabilities in Exim

CVEs referencing this url
http://www.securitytracker.com/id/1039873

Exim Infinite Loop in bdat_getc() Lets Remote Users Consume Excessive Memory Resources - SecurityTracker
Third Party Advisory;VDB Entry
https://www.debian.org/security/2017/dsa-4053

Debian -- Security Information -- DSA-4053-1 exim4
Third Party Advisory

CVEs referencing this url
https://bugs.exim.org/show_bug.cgi?id=2201

Bug 2201 – Exim handles BDAT data incorrectly and leads to crash
Exploit;Issue Tracking
http://openwall.com/lists/oss-security/2017/11/25/1

oss-security - Re: RCE in Exim reported
Mailing List

CVEs referencing this url

Products affected by CVE-2017-16944