CVE-2023-43622
Apache HTTP Server: DoS in HTTP/2 with initial windows size 0
02 Description
Apache HTTP Server: DoS in HTTP/2 with initial windows size 0
03 Exploitation and scoring
- Exploitation
- Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
- SSVC decision
- ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 68.81% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 99.3% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2023-10-23 06:50Z3 YR AGO
- Last updated
- 2025-02-13 17:13Z1 YR AGO
- Reserved
- 2023-09-20
- Assigning CNA
- apache
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-400Uncontrolled Resource ConsumptionClass
- Data version
- 5.1
- Document digest
- 6a49c60eba488ad4ce4bda538719e2c06cebf0f66da69e681197cafd4d161400
05 Affected products
06 References
- httpd.apache.orghttps://httpd.apache.org/security/vulnerabilities_24.html
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20231027-0011/
07 Fixed in
AlmaLinux 9
- mod_http2 Fixed in 2.0.26-1.el9
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 9
- mod_http2 Fixed in 2.0.26-1.el9
Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- apache2 Fixed in 2.4.59-1~deb12u1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- apache2 Fixed in 2.4.58-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- apache2 Fixed in 2.4.58-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.