CVE-2025-0343
HIGHDescription
Swift ASN.1 can be caused to crash when parsing certain BER/DER constructions. This crash is caused by a confusion in the ASN.1 library itself which assumes that certain objects can only be provided in either constructed or primitive forms, and will trigger a preconditionFailure if that constraint isn't met. Importantly, these constraints are actually required to be true in DER, but that correctness wasn't enforced on the early node parser side so it was incorrect to rely on it later on in decoding, which is what the library did. These crashes can be triggered when parsing any DER/BER format object. There is no memory-safety issue here: the crash is a graceful one from the Swift runtime. The impact of this is that it can be used as a denial-of-service vector when parsing BER/DER data from unknown sources, e.g. when parsing TLS certificates.
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
TridentStack Control tracks known vulnerabilities across your Windows, macOS, and Linux fleet and shows the fix as soon as one is published. See how it works
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Low risk: more likely to be exploited than 26% of all known CVEs.
References
Related Vulnerabilities
Other CWE-228 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2018-5381 | Medium | 6.5 | 30% | - | Fix |
| CVE-2021-38443 | Medium | 6.6 | 2.1% | - | Fix |
| CVE-2020-27847 | Critical | 9.8 | 1.7% | - | Fix |
| CVE-2021-36199 | Medium | 5.3 | 1.0% | - | - |
| CVE-2026-42100 | High | 7.5 | 0.7% | - | - |
| CVE-2024-21612 | High | 7.5 | 0.5% | - | Fix |
Common questions
How do I fix CVE-2025-0343?
No published fix for CVE-2025-0343 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2025-0343 being actively exploited?
Not that we know of. CVE-2025-0343 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.33% is the estimated probability that it will be exploited in the next 30 days. That is higher than 26% of all scored CVEs.
How severe is CVE-2025-0343?
CVE-2025-0343 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
Embed a live status badge for CVE-2025-0343
Markdown
[](https://tridentstack.com/cve/CVE-2025-0343)HTML
<a href="https://tridentstack.com/cve/CVE-2025-0343"><img src="https://tridentstack.com/cve/badge/CVE-2025-0343.svg" alt="CVE-2025-0343"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-03-24.