Vulnerability Name:

CVE-2016-6581 (CCN-125164)

Assigned:2016-08-04
Published:2016-08-04
Updated:2017-01-27
Summary: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.
CVSS v3 Severity:7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
7.5 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
CVSS v2 Severity:7.8 High (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-399
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2016-6581

Source: BID
Type: Third Party Advisory, VDB Entry
92315

Source: CCN
Type: BID-92315
Python HPACK CVE-2016-6581 Remote Denial of Service Vulnerability

Source: XF
Type: UNKNOWN
python-cve20166581-dos(125164)

Source: CCN
Type: Hyper Project Web site
hpack: HTTP/2 Header Compression for Python

Source: CCN
Type: Hyper Project Security Advisory
HPACK Bomb

Source: CONFIRM
Type: Mitigation, Vendor Advisory
https://python-hyper.org/hpack/en/latest/security/CVE-2016-6581.html

Vulnerable Configuration:Configuration 1:
  • cpe:/a:python:hpack:1.0:*:*:*:*:*:*:*
  • OR cpe:/a:python:hpack:2.0:*:*:*:*:*:*:*
  • OR cpe:/a:python:hpack:2.0.1:*:*:*:*:*:*:*
  • OR cpe:/a:python:hpack:2.1.1:*:*:*:*:*:*:*
  • OR cpe:/a:python:hpack:2.2:*:*:*:*:*:*:*
  • OR cpe:/a:python:hyper:0.4:*:*:*:*:*:*:*
  • OR cpe:/a:python:hyper:0.6:*:*:*:*:*:*:*

  • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:org.opensuse.security:def:615
    P
    Security update for xen (Important)
    2022-07-29
    oval:org.opensuse.security:def:3516
    P
    gtk2-data-2.24.31-9.6.28 on GA media (Moderate)
    2022-06-28
    oval:org.opensuse.security:def:95146
    P
    python3-hpack-3.0.0-3.2.1 on GA media (Moderate)
    2022-06-22
    oval:org.opensuse.security:def:113266
    P
    python36-hpack-4.0.0-1.6 on GA media (Moderate)
    2022-01-17
    oval:org.opensuse.security:def:106678
    P
    python36-hpack-4.0.0-1.6 on GA media (Moderate)
    2021-10-01
    oval:org.opensuse.security:def:101391
    P
    python3-hpack-3.0.0-3.2.1 on GA media (Moderate)
    2021-08-10
    oval:org.opensuse.security:def:2276
    P
    python3-hpack-3.0.0-3.2.1 on GA media (Moderate)
    2021-08-10
    oval:org.opensuse.security:def:63365
    P
    python3-hpack-3.0.0-3.2.1 on GA media (Moderate)
    2021-08-10
    oval:com.ubuntu.artful:def:20166581000
    V
    CVE-2016-6581 on Ubuntu 17.10 (artful) - medium.
    2017-01-10
    oval:com.ubuntu.cosmic:def:201665810000000
    V
    CVE-2016-6581 on Ubuntu 18.10 (cosmic) - medium.
    2017-01-10
    oval:com.ubuntu.bionic:def:20166581000
    V
    CVE-2016-6581 on Ubuntu 18.04 LTS (bionic) - medium.
    2017-01-10
    oval:com.ubuntu.bionic:def:201665810000000
    V
    CVE-2016-6581 on Ubuntu 18.04 LTS (bionic) - medium.
    2017-01-10
    oval:com.ubuntu.cosmic:def:20166581000
    V
    CVE-2016-6581 on Ubuntu 18.10 (cosmic) - medium.
    2017-01-10
    oval:com.ubuntu.xenial:def:201665810000000
    V
    CVE-2016-6581 on Ubuntu 16.04 LTS (xenial) - medium.
    2017-01-10
    oval:com.ubuntu.xenial:def:20166581000
    V
    CVE-2016-6581 on Ubuntu 16.04 LTS (xenial) - medium.
    2017-01-10
    BACK
    python hpack 1.0
    python hpack 2.0
    python hpack 2.0.1
    python hpack 2.1.1
    python hpack 2.2
    python hyper 0.4
    python hyper 0.6