Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability
CVE-2023-42116

8.1HIGH

Key Information:

Vendor

Exim

Status
Exim
Vendor
CVE Published:
3 May 2024

What is CVE-2023-42116?

A vulnerability has been identified in the Exim SMTP server that allows remote attackers to execute arbitrary code. This flaw arises from improper handling of NTLM challenge requests, which fails to validate the length of incoming user-supplied data before copying it to a fixed-size stack-based buffer. As a result, attackers can exploit this issue without requiring authentication, potentially allowing them to execute code in the context of the service account. Proper validation measures should be implemented to mitigate this risk.

Affected Version(s)

Exim exim 4.95

References

https://www.zerodayinitiative.com/advisories/ZDI-23-1470/
x_research-advisory

EPSS Score

6% chance of being exploited in the next 30 days.

CVSS V3.1

Score:
8.1
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.