How severe is CVE-2023-42115?

CVE-2023-42115 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-42115 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-42115?

CVE-2023-42115 affects Exim. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-42115?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2023-42115 have an EU (EUVD) identifier?

Yes. CVE-2023-42115 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-46574.

When was CVE-2023-42115 published?

CVE-2023-42115 was published on 2024-05-03 and last updated on 2026-06-17.

CVE-2023-42115

CVE-2023-42115 is a critical-severity vulnerability in Exim with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 10% places it in the 95th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 10% (95th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2023-46574
Weakness: CWE-787
Affected product: Exim
Published: 2024-05-03
Last modified: 2026-06-17

Description

Exim AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exim. Authentication is not required to exploit this vulnerability. The specific flaw exists within the smtp service, which listens on TCP port 25 by default. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of a buffer. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17434.

Frequently asked questions

What is CVE-2023-42115?: Exim AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exim. Authentication is not required to exploit this vulnerability. The specific flaw exists within the smtp service, which listens on TCP port 25 by default. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of a buffer. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17434.
How severe is CVE-2023-42115?: CVE-2023-42115 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-42115 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-42115?: CVE-2023-42115 affects Exim. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-42115?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2023-42115 have an EU (EUVD) identifier?: Yes. CVE-2023-42115 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-46574.
When was CVE-2023-42115 published?: CVE-2023-42115 was published on 2024-05-03 and last updated on 2026-06-17.

References

https://www.zerodayinitiative.com/advisories/ZDI-23-1469/

Affected products (1)

cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

193.202.11.112 (ipv4-addr)
76.12.128.249 (ipv4-addr)
50.116.72.139 (ipv4-addr)
166.62.41.190 (ipv4-addr)
160.187.147.124 (ipv4-addr)
132.148.155.138 (ipv4-addr)
77.221.151.241 (ipv4-addr)
37.221.254.200 (ipv4-addr)