SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2023-44487

HTTP/2 Rapid Reset Attack Vulnerability

KEVHIGH 7.5EPSS 100.0%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 31 October 2023). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
100.00% probability · 100th percentile
CISA KEV
Listed 10 October 2023 · due 31 October 2023
Weakness
CWE-400
Affected
siemens/simatic s7-1500 cpu 1518f-4 pn\/dp mfp firmware · siemens/sinec ins · siemens/sinec nms · siemens/st7 scadaconnect · siemens/ruggedcom ape1808 firmware · siemens/simatic s7-1500 cpu 1518-4 pn\/dp mfp firmware · siemens/siplus s7-1500 cpu 1518-4 pn\/dp mfp firmware · ietf/http · nghttp2/nghttp2 · netty/netty · envoyproxy/envoy · eclipse/jetty · caddyserver/caddy · golang/go · golang/http2 · golang/networking · f5/big-ip access policy manager · f5/big-ip advanced firewall manager · f5/big-ip advanced web application firewall · f5/big-ip analytics · +40 more
Source
cve@mitre.org

CISA notes

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. 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; https://blog.cloudflare.com/technical-breakdown-http2-rapid-reset-ddos-attack/; https://nvd.nist.gov/vuln/detail/CVE-2023-44487

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.