VulnerabilityDeferred

CVE-2023-45288

An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames.

HIGH 7.5EPSS 92.0%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 92.0%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.

Description

An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 91.97% probability · 100th percentile
CISA KEV: Not listed
Source: security@golang.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.