user/nghttp2: CVE-2020-11080: DoS via large SETTINGS frame
| Bugzilla ID | 299 |
| Alias(es) | CVE-2020-11080 |
| Reporter | Max Rees (sroracle) |
| Assignee | Max Rees (sroracle) |
| Reported | 2020-06-09 19:07:09 -0500 |
| Modified | 2020-06-15 16:39:00 -0500 |
| Status | RESOLVED FIXED |
| Version | 1.0-RC1 |
| Hardware | Adélie Linux / All |
| Importance | --- / major |
| URL | https://nvd.nist.gov/vuln/detail/CVE-2020-11080 |
| See also | https://bts.adelielinux.org/show_bug.cgi?id=300 |
Description
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.
Fixed in >= 1.41.0
https://github.com/nghttp2/nghttp2/security/advisories/GHSA-q5wr-xfw9-q7xr
https://github.com/nghttp2/nghttp2/commit/336a98feb0d56b9ac54e12736b18785c27f75090
https://github.com/nghttp2/nghttp2/commit/f8da73bd042f810f34d19f9eae02b46d870af394