CVE-2020-0601
A spoofing vulnerability exists in the way Windows CryptoAPI (Crypt32.dll) validates Elliptic Curve Cryptography (ECC) certificates.An attacker could exploit the vulnerability by using a spoofed code-signing certificate to sign a malicious executable, making it appear the file was from a trusted, legitimate source, aka 'Windows CryptoAPI Spoofing Vulnerability'.
- CVSS
- 8.1Highscored by CISA
- Exploited in the wild
- Yes, in CISA KEV since 3 Nov 2021CISA deadline for US federal agencies: 3 May 2022public exploit code
- EPSS
- 89.1%chance of exploitation in the next 30 daystop 0.3% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 14 Jan 2020analysed here 12 Nov 2026
Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)
Summary
Triage
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Microsoft Windows | 10 Version 1803 for 32-bit Systems10 Version 1803 for x64-based Systems10 Version 1803 for ARM64-based Systems10 Version 1809 for 32-bit Systems10 Version 1809 for x64-based Systems10 Version 1809 for ARM64-based Systems10 Version 1709 for 32-bit Systems10 Version 1709 for x64-based Systems10 Version 1709 for ARM64-based Systems10 for 32-bit Systems10 for x64-based Systems10 Version 1607 for 32-bit Systems10 Version 1607 for x64-based SystemsVendor says fixed in: not stated | |
| Microsoft Windows Server | version 1803 (Core Installation)20192019 (Core installation)20162016 (Core installation)Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- microsoft:windows_10_1507
- microsoft:windows_10_1607
- microsoft:windows_10_1709
- microsoft:windows_10_1803
- microsoft:windows_10_1809
- microsoft:windows_10_1903
- microsoft:windows_10_1909
- microsoft:windows_server_1803
- microsoft:windows_server_1903
- microsoft:windows_server_1909
- microsoft:windows_server_2016
- microsoft:windows_server_2019
- golang:go
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Partly. The bug can be reached over the network, so generic WAF rules may stop some attacks. Its weakness type is unknown, so we cannot be more precise.
Also consider: patch
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 3 Nov 2021.
- CISA due date
- 3 May 2022, the remediation deadline for US federal agencies
- CISA required action
- Apply updates per vendor instructions.
- Public exploit code
- Yes: 1 on Exploit-DB · 35 GitHub proofs of concept
- CISA SSVC
- exploitation active, automatable no, technical impact totalAssessed by CISA 7 Feb 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Exploit-DB
GitHub proofs of concept
- ly4k/CurveBall890 stars
- kudelskisecurity/chainoffools336 stars
- gentilkiwi/curveball78 stars
- saleemrashid/badecparams66 stars
and 31 more repositories
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 14 Jan 2020First public exploit or proof of concept
- 14 Jan 2020Published1 day later
- 3 Nov 2021Added to CISA KEV (exploited in the wild)658 days (about 2 years) later
- 3 May 2022CISA remediation due date (US federal agencies)181 days (about 6 months) later
- 7 Feb 2025CISA SSVC assessment: exploitation active1,012 days (about 3 years) later
- 21 Oct 2025CVE record last updated256 days (about 9 months) later
- 12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | NoneThe attacker needs no prior access. | The attacker needs no prior access. |
| User interaction | RequiredA victim must click, open or otherwise cooperate. | A victim must click, open or otherwise cooperate. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | NoneThe service stays up. | The service stays up. |
Common questions
Is CVE-2020-0601 being exploited?
Yes. CVE-2020-0601 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2020-0601?
CVE-2020-0601 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2020-0601?
Yes. A fix has been recorded for CVE-2020-0601. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2020-0601 affect?
CVE-2020-0601 affects microsoft:windows_10_1507, microsoft:windows_10_1607, microsoft:windows_10_1709, microsoft:windows_10_1803, and 9 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
4 references in the CVE record, grouped by the tags the record gives them.
Other links (4)
- portal.msrc.microsoft.com /en-US/security-guidance/advisory/CVE-2020-0601
- packetstormsecurity.com /files/155961/CurveBall-Microsoft-Windows-CryptoAPI-Spoofing-Proof-Of-Concept.ht
- packetstormsecurity.com /files/155960/CurveBall-Microsoft-Windows-CryptoAPI-Spoofing-Proof-Of-Concept.ht
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-0601
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Exploit-DB: published exploits
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
Similar CVEs
Get CVEs like this by email. Join the free digest: the CVEs we flag as major, all CVSS 8.0 or higher, in up to three emails a day (sent at 05:00, 11:00 and 15:00 UTC). Matching alerts to the products you run needs an account, and accounts are invite-only during the beta.