Use After Free in Apache Http_server

CVE-2017-9789

When under stress, closing many connections, the HTTP/2 handling code in Apache httpd 2.4.26 would sometimes access memory after it has been freed, resulting in potentially erratic behaviour.

Vulnerability class: Use-After-Free

EPSS: 0.101 (93.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/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

Frequently asked questions

What is CVE-2017-9789?
CVE-2017-9789 is a high-severity vulnerability in Apache Http_server, classified under Use After Free. CVSS score: 7.5/10. Published 2017-07-13.
How severe is CVE-2017-9789?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2017-9789 known to be exploited?
37 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.