VDB
CVE-2016-6581
CVE-2016-6581
PUBLISHED
CVSS 7.5 HIGH
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.
EPSS 1.83% · 78.0th percentile
Risk Scores
CVSS 3.0
7.5
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score
1.83%
78.0th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:16.04:LTS | python-hpack | 1.1.0-1, 2.0.1-1, 2.1.0-1 |
Timeline
- Jan 10, 2017 CVE Published
- Feb 4, 2022 EPSS Score
- Mar 29, 2022 EPSS Score
- May 21, 2022 EPSS Score
- Jul 13, 2022 EPSS Score
- Sep 5, 2022 EPSS Score
- Oct 28, 2022 EPSS Score
- Dec 20, 2022 EPSS Score
- Feb 11, 2023 EPSS Score
- Apr 5, 2023 EPSS Score
- May 28, 2023 EPSS Score
- Jul 20, 2023 EPSS Score
References
- https://ubuntu.com/security/CVE-2016-6581 third-party-advisory
- https://github.com/python-hyper/hpack/pull/56 third-party-advisory
- http://www.openwall.com/lists/oss-security/2016/08/04/3 third-party-advisory
- https://www.cve.org/CVERecord?id=CVE-2016-6581 third-party-advisory