CVE-2016-6581
HIGH 7.5
At a glance
- Source
- NVD
- EPSS
- EPSS 1.83 % · percentile 79 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- mitre
- NVD status
- Modified
Description
A HTTP/2 implementation built using any version of the Python HPACK library between v1.0.0 and v2.2.0 could be targeted for a denial of service attack, specifically a so-called "HPACK Bomb" attack. This attack occurs when an attacker inserts a header field that is exactly the size of the HPACK dynamic header table into the dynamic header table. The attacker can then send a header block that is simply repeated requests to expand that field in the dynamic table. This can lead to a gigantic compression ratio of 4,096 or better, meaning that 16kB of data can decompress to 64MB of data on the target machine.
Weaknesses (CWE)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.0 | HIGH 7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 2.0 | HIGH 7.8 | AV:N/AC:L/Au:N/C:N/I:N/A:C | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-ffq8-576r-v26g — HPACK Denial of Service vulnerability (HPACK Bomb)
- PYSEC-2017-87 — A HTTP/2 implementation built using any version of the Python HPACK library between v1.0.0 and v2.2.0 could be targeted for a denial of service attack, specific
European references
- ENISA EUVD · EUVD-2017-0059
- GCVE · GCVE-0-2016-6581
CERT-FR advisories
- CERTFR-2022-AVI-267 — Multiples vulnérabilités dans Juniper Networks Junos Space · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:python:hpack:1.0:*:*:*:*:*:*:*cpe:2.3:a:python:hpack:2.0:*:*:*:*:*:*:*cpe:2.3:a:python:hpack:2.0.1:*:*:*:*:*:*:*cpe:2.3:a:python:hpack:2.1.1:*:*:*:*:*:*:*cpe:2.3:a:python:hpack:2.2:*:*:*:*:*:*:*cpe:2.3:a:python:hyper:0.4:*:*:*:*:*:*:*cpe:2.3:a:python:hyper:0.6:*:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| affected n/a |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |