CVE-2023-44487
IETF — HTTP/2 Rapid Reset Attack Vulnerability
IETF · in CISA KEV since 2023-10-10
KEV since 2023 · listed over a yearCISA KEVActively Exploited
84
EVRS 84 of 100 Urgent
Patch This Cycle
Rank 458 of 2,960 tracked
Why it scores 84
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and an EPSS probability of 0.999.
- CISA KEVApplied
- RansomwareDid not apply
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyDid not apply
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
No fixed version identified yetCISA required action
- This vulnerability affects a common open-source component, third-party library, or protocol used by different products. For more information, please see: HTTP/2 Rapid Reset Vulnerability, CVE-2023-44487 | CISA: https://www.cisa.gov/news-events/alerts/2023/10/10/http2-rapid-reset-vulnerability-cve-2023-44487
- blog.cloudflare.com/…/technical-breakdown-http2-rapid-reset-ddos-attack
- nvd.nist.gov/…/CVE-2023-44487
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 7.5 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.999 (99.99th pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Unknown or none | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2023-10-31 · KEV since 2023 · listed over a year | CISA KEV |
Description
What CISA says to do
- This vulnerability affects a common open-source component, third-party library, or protocol used by different products. For more information, please see: HTTP/2 Rapid Reset Vulnerability, CVE-2023-44487 | CISA: https://www.cisa.gov/news-events/alerts/2023/10/10/http2-rapid-reset-vulnerability-cve-2023-44487
- blog.cloudflare.com/…/technical-breakdown-http2-rapid-reset-ddos-attack
- nvd.nist.gov/…/CVE-2023-44487
