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Security Advisory

USN-5199-1: Python vulnerabilities

Severity

Medium

Vendor

Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 18.04

Description

It was discovered that the urllib.request.AbstractBasicAuthHandler class in Python contains regex with a quadratic worst-case time complexity. Specially crafted traffic from a malicious HTTP server could cause a regular expression denial of service (ReDoS) condition for a client. (CVE-2021-3733) It was discovered that the Python urllib http client could enter into an infinite loop when incorrectly handling certain server responses (100 Continue response). Specially crafted traffic from a malicious HTTP server could cause a denial of service (DoS) condition for a client. (CVE-2021-3737)

CVEs contained in this USN include: CVE-2021-3733, CVE-2021-3737.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

  • Bionic Stemcells
    • 1.x versions prior to 1.51
    • All other stemcells not listed.
  • cflinuxfs3
    • All versions prior to 0.271.0
  • CF Deployment
    • All versions prior to 18.0.0

Mitigation

Users of affected products are strongly encouraged to follow the mitigations below. The Cloud Foundry project recommends upgrading the following releases:

  • Bionic Stemcells
    • Upgrade 1.x versions to 1.51 or greater
    • All other stemcells should be upgraded to the latest version available on bosh.io.
  • cflinuxfs3
    • Upgrade all versions to 0.271.0 or greater
  • CF Deployment
    • Upgrade all versions to 18.0.0 or greater

History

2022-03-08: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR

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