CVE-2016-6581
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2016-6581
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2016-6581.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2016-6581
- Aliases
- Related
- Published
- 2017-01-10T15:59:00Z
- Modified
- 2025-04-20T03:21:20.418835Z
- Downstream
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
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.
- References
Affected packages
Debian:11 / python-hpack
Package
- Name
- python-hpack
- Purl
- pkg:deb/debian/python-hpack?arch=source
Debian:12 / python-hpack
Package
- Name
- python-hpack
- Purl
- pkg:deb/debian/python-hpack?arch=source
Debian:13 / python-hpack
Package
- Name
- python-hpack
- Purl
- pkg:deb/debian/python-hpack?arch=source