CVE-2020-28020 : Exim 4 before 4.92 allows Integer Overflow to Buffer Overflow, in which an unauthenticated remote attacker can execute a

Exim 4 before 4.92 allows Integer Overflow to Buffer Overflow, in which an unauthenticated remote attacker can execute arbitrary code by leveraging the mishandling of continuation lines during header-length restriction.

Published 2021-05-06 13:15:10

Updated 2022-06-28 14:11:45

Source MITRE

View at NVD, CVE.org

Vulnerability category: OverflowExecute code

Products affected by CVE-2020-28020

Exim » Exim
Versions from including (>=) 4.00 and before (<) 4.92
cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*
Matching versions

Threat overview for CVE-2020-28020

Top countries where our scanners detected CVE-2020-28020

Top open port discovered on systems with this issue 80

IPs affected by CVE-2020-28020 46,329

Threat actors abusing to this issue? Yes

Find out if you^* are affected by CVE-2020-28020!

^*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-2020-28020

EPSS FAQ

3.14%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 91 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2020-28020

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
7.5	HIGH	AV:N/AC:L/Au:N/C:P/I:P/A:P	10.0	6.4	NIST
Access Vector: Network Access Complexity: Low Authentication: None Confidentiality Impact: Partial Integrity Impact: Partial Availability Impact: Partial
9.8	CRITICAL	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	3.9	5.9	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: High

CWE ids for CVE-2020-28020

CWE-190 Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Assigned by: nvd@nist.gov (Primary)

References for CVE-2020-28020

http://www.openwall.com/lists/oss-security/2021/07/25/1

oss-security - CVE-2020-28020: Integer overflow in Exim that can lead to RCE: Some questions to the Qualys researchers who designed the exploit
Mailing List;Third Party Advisory
https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28020-HSIZE.txt

Patch;Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/08/03/1

oss-security - Re: CVE-2020-28020: Integer overflow in Exim that can lead to RCE: Some questions to the Qualys researchers who designed the exploit
Mailing List;Third Party Advisory