CVE-2023-42114 | Exim NTLM Challenge Out-Of-Bounds Read Information Disclosure Vulnerability

Exim NTLM Challenge Out-Of-Bounds Read Information Disclosure Vulnerability. This vulnerability allows remote attackers to disclose sensitive information on affected installations of Exim. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of NTLM challenge requests. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated data structure. An attacker can leverage this vulnerability to disclose information in the context of the service account. . Was ZDI-CAN-17433.

Published: 2024-05-03 Last update: 2025-11-04 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-42114 is rated Moderate Risk (54.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 13.89%, 94th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-42114

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-28 13.16% 13.89% +0.73%
2 2025-12-27 13.89% 13.16% -0.73%
3 2025-11-21 — 13.89% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-42114

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
3.7 3.0 LOW
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 1.4 [email protected]

Weakness enumeration for CVE-2023-42114

OS Trackers for CVE-2023-42114

vendor priority summary link
alpine — CVE-2023-42114: 1 source package rows (exim); 31 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 25. https://security.alpinelinux.org/vuln/CVE-2023-42114
debian not yet assigned CVE-2023-42114 not yet assigned priority: Debian including 1 source packages (exim4), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-42114
gentoo high CVE-2023-42114: 1 GLSA(s) (202402-18), 1 atom(s) (mail-mta/exim); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-42114
redhat low — https://access.redhat.com/security/cve/CVE-2023-42114
ubuntu medium CVE-2023-42114 medium priority: Ubuntu including 1 source packages (exim4), 8 status rows across 8 suites (bionic, focal, jammy, lunar, mantic, trusty, upstream, xenial): released 8. https://ubuntu.com/security/CVE-2023-42114

Affected software / configurations for CVE-2023-42114

Vendor Product Version Raw CPE
exim exim < 4.96.1 cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*

References for CVE-2023-42114

cvelogic Threat Intelligence