How severe is CVE-2023-42118?

CVE-2023-42118 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-42118 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 51% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-42118?

CVE-2023-42118 affects Libspf2 Project Libspf2. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-42118?

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

Does CVE-2023-42118 have an EU (EUVD) identifier?

Yes. CVE-2023-42118 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-46577.

When was CVE-2023-42118 published?

CVE-2023-42118 was published on 2024-05-03 and last updated on 2026-06-17.

CVE-2023-42118

CVE-2023-42118 is a high-severity vulnerability in Libspf2 Project Libspf2 with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 51% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-191.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 51% (99th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2023-46577
Weakness: CWE-191
Affected product: Libspf2 Project Libspf2
Published: 2024-05-03
Last modified: 2026-06-17

Description

Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of SPF macros. When parsing SPF macros, the process does not properly validate user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17578.

Frequently asked questions

What is CVE-2023-42118?: Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of SPF macros. When parsing SPF macros, the process does not properly validate user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17578.
How severe is CVE-2023-42118?: CVE-2023-42118 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-42118 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 51% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-42118?: CVE-2023-42118 affects Libspf2 Project Libspf2. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-42118?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2023-42118 have an EU (EUVD) identifier?: Yes. CVE-2023-42118 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-46577.
When was CVE-2023-42118 published?: CVE-2023-42118 was published on 2024-05-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:libspf2_project:libspf2:-:*:*:*:*:*:*:*

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