CISA KEV · Known exploitedHigh

CVE-2023-44487

IETF HTTP/2

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: 7.5
EPSS: 100.0%
CISA KEV: Listed
Published: 2023.10.10

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability100.0%

Technical severityCVSS 7.5

Vulnerability overview

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.

Affected product and versions

Product: IETF HTTP/2
Affected versions: 2.0, V3.1.5, >= 3.1.5, < 1.0, 1.0, < 3.0, < 1.1, < 1.57.0, < 4.1.100, 1.24.10, 1.25.9, 1.26.4, 1.27.0, < 9.4.53, >= 10.0.0 < 10.0.17, >= 11.0.0 < 11.0.17, >= 12.0.0 < 12.0.2, < 2.7.5
Fixed versions: 1.0, 3.0, 1.1, 1.57.0, 4.1.100, 9.4.53, 10.0.17, 11.0.17, 12.0.2, 2.7.5, 1.20.10, 1.21.3, 0.17.0, r29, 1.28.0, 1.56.3, 1.58.3, 6.0.23, 7.0.12, 2023-10-08

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Due date: 2023.10.31

1
Identify
Confirm that IETF HTTP/2 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE: CWE-400
KEV added: 2023.10.10
Ransomware use: 미확인