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Uncaught Exception (due to a data race) leads to process termination in Waitress

Moderate severity GitHub Reviewed Published May 30, 2022 in Pylons/waitress • Updated Jan 27, 2023

Package

pip waitress (pip)

Affected versions

>= 2.1.0, < 2.1.2

Patched versions

2.1.2

Description

Impact

Waitress may terminate early due to a thread closing a socket while the main thread is about to call select(). This will lead to the main thread raising an exception that is not handled and then causing the entire application to be killed.

Patches

This issue has been fixed in Waitress 2.1.2 by no longer allowing the WSGI thread to close the socket, instead it is always delegated to the main thread.

Workarounds

There is no work-around, however users using waitress behind a reverse proxy server are less likely to have issues if the reverse proxy always reads the full response.

For more information

If you have any questions or comments about this advisory:

References

@digitalresistor digitalresistor published to Pylons/waitress May 30, 2022
Published by the National Vulnerability Database May 31, 2022
Published to the GitHub Advisory Database Jun 2, 2022
Reviewed Jun 2, 2022
Last updated Jan 27, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.187%
(57th percentile)

CVE ID

CVE-2022-31015

GHSA ID

GHSA-f5x9-8jwc-25rw

Source code

Credits

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