Python: Denial of service - Remote with user interaction

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                         ZMCIRT Vulnerability Bulletin

                             ZMC-2021.09.17.1700
 Python: Denial of service - Remote with user interaction
                               17th Sep 2021

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Product:           Python
Publisher:         Ubuntu
Operating System:  Ubuntu
                   UNIX variants (UNIX, Linux, OSX)
                   Windows
Impact/Access:     Denial of Service -- Remote with User Interaction
Resolution:        Patch/Upgrade
CVE Names:         CVE-2021-3737 CVE-2021-3733 

Original Bulletin: 
   https://ubuntu.com/security/notices/USN-5083-1

Comment: This advisory references vulnerabilities in products which run on 
         platforms other than Ubuntu. It is recommended that administrators 
         running Python check for an updated version of the software for 
         their operating system.



USN-5083-1: Python vulnerabilities
16 September 2021

Several security issues were fixed in Python.
Releases

  o Ubuntu 16.04 ESM
  o Ubuntu 14.04 ESM

Packages

  o python3.4 - An interactive high-level object-oriented language
  o python3.5 - An interactive high-level object-oriented language

Details

It was discovered that Python incorrectly handled certain RFCs.
An attacker could possibly use this issue to cause a denial of service.
This issue only affected Ubuntu 16.04 ESM. ( CVE-2021-3733 )

It was discovered that Python incorrectly handled certain
server responses. An attacker could possibly use this issue to
cause a denial of service. ( CVE-2021-3737 )

Update instructions

The problem can be corrected by updating your system to the following package
versions:

Ubuntu 16.04

  o python3.5 - 3.5.2-2ubuntu0~16.04.13+esm1
    Available with UA Infra or UA Desktop
  o python3.5-minimal - 3.5.2-2ubuntu0~16.04.13+esm1
    Available with UA Infra or UA Desktop

Ubuntu 14.04

  o python3.4-minimal - 3.4.3-1ubuntu1~14.04.7+esm11
    Available with UA Infra or UA Desktop
  o python3.4 - 3.4.3-1ubuntu1~14.04.7+esm11
    Available with UA Infra or UA Desktop

In general, a standard system update will make all the necessary changes.

References

  o CVE-2021-3733
  o CVE-2021-3737


 
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in this document is accurate.  However, the decision to use the information
described is the responsibility of each user or organisation. The decision to
follow or act on information or advice contained in this security bulletin is
the responsibility of each user or organisation, and should be considered in
accordance with your organisation's site policies and procedures. ZMCERT
takes no responsibility for consequences which may arise from following or
acting on information or advice contained in this security bulletin.

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