Resource exhaustion in Nghttp2

CVE-2020-11080

In nghttp2 before version 1.41.0, the overly large HTTP/2 SETTINGS frame payload causes denial of service. The proof of concept attack involves a malicious client constructing a SETTINGS frame with a length of 14,400 bytes (2400 individual settings entries) over and over again. The attack causes the CPU to spike at 100%. nghttp2 v1.41.0 fixes this vulnerability. There is a workaround to this vulnerability. Implement nghttp2_on_frame_recv_callback callback, and if received frame is SETTINGS frame and the number of settings entries are large (e.g., > 32), then drop the connection.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.053 (92.3th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 92.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2020-11080: held from 0.053 to 0.053.

EPSS over last 30 days · oldest: 0.053 · newest: 0.053 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-11080?
CVE-2020-11080 is a low-severity vulnerability in Nghttp2, classified under CWE-707. CVSS score: 3.7/10. Published 2020-06-03.
How severe is CVE-2020-11080?
Low severity. CVSS v3 base score is 3.7 out of 10.
Is CVE-2020-11080 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.