Resource exhaustion in Apache HTTP Server
CVE-2019-9517
Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.279 (98.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cret@cert.org (US Government Resource, x_refsource_CERT-VN, Third Party Advisory, third-party-advisory)
- cret@cert.org (Third Party Advisory, x_refsource_MISC)
- cret@cert.org (mailing-list, x_refsource_MLIST)
- cret@cert.org (mailing-list, x_refsource_MLIST)
- cret@cert.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- cret@cert.org (mailing-list, x_refsource_MLIST)
- cret@cert.org (mailing-list, x_refsource_MLIST)
- cret@cert.org (x_refsource_CONFIRM, Third Party Advisory)
- cret@cert.org (x_refsource_CONFIRM, Third Party Advisory)
- cret@cert.org (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-9517?
- CVE-2019-9517 is a high-severity vulnerability in Apache HTTP Server, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2019-08-13.
- How severe is CVE-2019-9517?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2019-9517 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.