How severe is CVE-2018-16149?

CVE-2018-16149 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-16149 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-16149?

CVE-2018-16149 affects Axtls Project Axtls. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-16149?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-16149 published?

CVE-2018-16149 was published on 2018-11-07 and last updated on 2026-06-17.

CVE-2018-16149

CVE-2018-16149 is a medium-severity vulnerability in Axtls Project Axtls with a CVSS 3.x base score of 5.9. 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-347.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 4.3
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Axtls Project Axtls
Published: 2018-11-07
Last modified: 2026-06-17

Description

In sig_verify() in x509.c in axTLS version 2.1.3 and before, the PKCS#1 v1.5 signature verification blindly trusts the declared lengths in the ASN.1 structure. Consequently, when small public exponents are being used, a remote attacker can generate purposefully crafted signatures (and put them on X.509 certificates) to induce illegal memory access and crash the verifier.

Frequently asked questions

What is CVE-2018-16149?: In sig_verify() in x509.c in axTLS version 2.1.3 and before, the PKCS#1 v1.5 signature verification blindly trusts the declared lengths in the ASN.1 structure. Consequently, when small public exponents are being used, a remote attacker can generate purposefully crafted signatures (and put them on X.509 certificates) to induce illegal memory access and crash the verifier.
How severe is CVE-2018-16149?: CVE-2018-16149 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-16149 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-16149?: CVE-2018-16149 affects Axtls Project Axtls. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-16149?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-16149 published?: CVE-2018-16149 was published on 2018-11-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:axtls_project:axtls:*:*:*:*:*:*:*:*

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