CVE-2016-6580: Priority Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-h3q4-6j7f-r24c
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CVSS 7.5
CWE-770
Published
Advisory Summary

CVE-2016-6580 is a MODERATE (CVSS 7.5) denial of service vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Priority libraries in the PyPI ecosystem. The issue involves priority vulnerable to denial of service. Remediation is available by upgrading affected packages to version 1.2.0.

CVE-2016-6580 at a Glance

CVE Identifier CVE-2016-6580
GHSA Identifier GHSA-h3q4-6j7f-r24c
Severity MODERATE
CVSS v3.1 Base Score 7.5
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Priority
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2016-6580

To remediate this vulnerability, upgrade all affected Priority dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

priority fixed: 1.2.0 
pip install priority>=1.2.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show priority

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2016-6580, inspect your installed packages using pip:

pip show priority

Analyze the terminal output to locate any version of Priority in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.2.0), your application is affected.

Note: The pip show priority command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Priority, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A HTTP/2 implementation built using any version of the Python priority library prior to version 1.2.0 could be targeted by a malicious peer by having that peer assign priority information for every possible HTTP/2 stream ID. The priority tree would happily continue to store the priority information for each stream, and would therefore allocate unbounded amounts of memory. Attempting to actually use a tree like this would also cause extremely high CPU usage to maintain the tree.

CVE-2016-6580 Affected Priority Versions

1 component(s)
Fixed Versions:
1.2.0
Product / Package Ecosystem Affected Versions Fixed Version
priority
pypi/priority
PyPI
< 1.2.0
1.2.0

References

NVD — CVE-2016-6580 NVD
https://nvd.nist.gov/vuln/detail/CVE-2016-6580
Security Fix Commit FIX COMMIT
https://github.com/python-hyper/priority/commit/7d01a7dc4db83bce50f20d47caf4f37b403a3ecd
Priority Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/priority/PYSEC-2017-93.yaml
Priority Source Repository REPOSITORY
https://github.com/python-hyper/priority
Priority Security Information SECURITY
https://python-hyper.org/priority/en/latest/security/CVE-2016-6580.html
Priority Security Information SECURITY
https://web.archive.org/web/20160806004329/http://www.securityfocus.com/bid/92311

Frequently Asked Questions

What is CVE-2016-6580?
CVE-2016-6580 is a security vulnerability in Priority involving priority vulnerable to denial of service under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Priority versions are affected?
Affected versions include releases prior to 1.2.0 across affected packages: priority.
What version fixes CVE-2016-6580?
Upgrading to 1.2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is priority affected?
Yes, priority is affected in releases prior to 1.2.0. Upgrade your dependency to 1.2.0 or later.
What is the CVSS score of CVE-2016-6580?
CVE-2016-6580 has a CVSS v3.1 base score of 7.5 (MODERATE) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2016-6580?
CVE-2016-6580 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check PyPI dependencies for CVE-2016-6580?
Run the dependency tree command: 'pip show priority'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-h3q4-6j7f-r24c",
  "modified" : "2024-08-30T23:37:23Z",
  "published" : "2022-05-17T03:02:35Z",
  "aliases" : [ "CVE-2016-6580" ],
  "summary" : "priority vulnerable to denial of service",
  "details" : "A HTTP/2 implementation built using any version of the Python priority library prior to version 1.2.0 could be targeted by a malicious peer by having that peer assign priority information for every possible HTTP/2 stream ID. The priority tree would happily continue to store the priority information for each stream, and would therefore allocate unbounded amounts of memory. Attempting to actually use a tree like this would also cause extremely high CPU usage to maintain the tree.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "priority"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2016-6580"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-hyper/priority/commit/7d01a7dc4db83bce50f20d47caf4f37b403a3ecd"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/priority/PYSEC-2017-93.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/python-hyper/priority"
  }, {
    "type" : "WEB",
    "url" : "https://python-hyper.org/priority/en/latest/security/CVE-2016-6580.html"
  }, {
    "type" : "WEB",
    "url" : "https://web.archive.org/web/20160806004329/http://www.securityfocus.com/bid/92311"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-08-30T23:37:23Z",
    "nvd_published_at" : "2017-01-10T15:59:00Z"
  }
}