CVE-2024-31309: Apache Traffic Server: HTTP/2 CONTINUATION frames can be utilized for DoS attack

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 94.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-10 · updated 2026-06-17
Weakness: CWE-20

Description

HTTP/2 CONTINUATION DoS attack can cause Apache Traffic Server to consume more resources on the server. Version from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.3 are affected. Users can set a new setting (proxy.config.http2.max_continuation_frames_per_minute) to limit the number of CONTINUATION frames per minute. ATS does have a fixed amount of memory a request can use and ATS adheres to these limits in previous releases. Users are recommended to upgrade to versions 8.1.10 or 9.2.4 which fixes the issue.

Affected products

Apache Software Foundation Apache Traffic Server: from 8.0.0 before 8.1.10; from 9.0.0 before 9.2.4 — fixed in 8.1.10, 9.2.4
Debian Linux: 10.0
Fedoraproject Fedora: 38, 39, 40

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache Traffic Server 8.1.10, 9.2.4. Check the vendor advisory for mitigations.

References

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