How severe is CVE-2024-27354?

CVE-2024-27354 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2024-27354 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-27354?

CVE-2024-27354 primarily affects Phpseclib. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-27354?

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-2024-27354 have an EU (EUVD) identifier?

Yes. CVE-2024-27354 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-0936.

When was CVE-2024-27354 published?

CVE-2024-27354 was published on 2024-03-01 and last updated on 2026-06-17.

CVE-2024-27354

CVE-2024-27354 is a high-severity vulnerability in Phpseclib with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-0936
Weakness: CWE-400
Affected product: Phpseclib
Published: 2024-03-01
Last modified: 2026-06-17

Description

An issue was discovered in phpseclib 1.x before 1.0.23, 2.x before 2.0.47, and 3.x before 3.0.36. An attacker can construct a malformed certificate containing an extremely large prime to cause a denial of service (CPU consumption for an isPrime primality check). NOTE: this issue was introduced when attempting to fix CVE-2023-27560.

Frequently asked questions

What is CVE-2024-27354?: An issue was discovered in phpseclib 1.x before 1.0.23, 2.x before 2.0.47, and 3.x before 3.0.36. An attacker can construct a malformed certificate containing an extremely large prime to cause a denial of service (CPU consumption for an isPrime primality check). NOTE: this issue was introduced when attempting to fix CVE-2023-27560.
How severe is CVE-2024-27354?: CVE-2024-27354 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-27354 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-27354?: CVE-2024-27354 primarily affects Phpseclib. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-27354?: 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-2024-27354 have an EU (EUVD) identifier?: Yes. CVE-2024-27354 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-0936.
When was CVE-2024-27354 published?: CVE-2024-27354 was published on 2024-03-01 and last updated on 2026-06-17.

References

EU advisories (EUVD)

Affected products (2)

cpe:2.3:a:phpseclib:phpseclib:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

More vulnerabilities in Phpseclib

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CVE-2023-49316 — High (CVSS 7.5): In Math/BinaryField.php in phpseclib 3 before 3.0.34, excessively large degrees can lead to a denial of service.
CVE-2023-27560 — High (CVSS 7.5): Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.
CVE-2021-30130 — High (CVSS 7.5): phpseclib before 2.0.31 and 3.x before 3.0.7 mishandles RSA PKCS#1 v1.5 signature verification.
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