VDB

CVE-2016-6581

CVE-2016-6581 PUBLISHED

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 0.37% · 59.4th percentile

Risk Scores

EPSS Score
0.37%
59.4th percentile

Affected Products

VendorProductVersions
Ubuntu:16.04:LTSpython-hpack1.1.0-1, 2.0.1-1, 2.1.0-1

Exploit Intelligence

Timeline

  • Jan 10, 2017 CVE Published
  • Aug 27, 2021 CVE Updated
  • Feb 4, 2022 EPSS Score
  • Mar 29, 2022 EPSS Score
  • May 20, 2022 EPSS Score
  • Jul 12, 2022 EPSS Score
  • Sep 3, 2022 EPSS Score
  • Oct 26, 2022 EPSS Score
  • Dec 18, 2022 EPSS Score
  • Feb 8, 2023 EPSS Score
  • Mar 7, 2023 EPSS Score
  • Apr 2, 2023 EPSS Score
Open in Interactive Console →
$ Console Community · 100/wk Open console ›