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Use of "infinity" as an input to datetime and date fields causes infinite loop in pydantic

Low severity GitHub Reviewed Published May 11, 2021 in pydantic/pydantic • Updated Sep 7, 2023

Package

pip pydantic (pip)

Affected versions

>= 1.8.0, < 1.8.2
>= 1.7.0, < 1.7.4
< 1.6.2

Patched versions

1.8.2
1.7.4
1.6.2

Description

Impact

Passing either 'infinity', 'inf' or float('inf') (or their negatives) to datetime or date fields causes validation to run forever with 100% CPU usage (on one CPU).
Patches

Pydantic is be patched with fixes available in the following versions:

v1.8.2
v1.7.4
v1.6.2

All these versions are available on pypi, and will be available on conda-forge soon.

See the changelog for details.
Workarounds

If you absolutely can't upgrade, you can work around this risk using a validator to catch these values, brief demo:

from datetime import date
from pydantic import BaseModel, validator

class DemoModel(BaseModel):
date_of_birth: date

@validator('date_of_birth', pre=True)
def skip_infinite_values(cls, v):
    try:
        seconds = float(v)
    except (ValueError, TypeError):
        return v
    else:
        if seconds == float('inf'):
            return date.max
        elif seconds == float('-inf'):
            return date.min
        else:
            return seconds

Note: this is not an ideal solution (in particular you'll need a slightly different function for datetimes), instead of a hack like this you should upgrade pydantic.

If you are not using v1.8.x, v1.7.x or v1.6.x and are unable to upgrade to a fixed version of pydantic, please create an issue requesting a back-port, and we will endeavour to release a patch for earlier versions of pydantic.
References

This was fixed in commit 7e83fdd.

References

@samuelcolvin samuelcolvin published to pydantic/pydantic May 11, 2021
Reviewed May 13, 2021
Published by the National Vulnerability Database May 13, 2021
Published to the GitHub Advisory Database May 13, 2021
Last updated Sep 7, 2023

Severity

Low
3.3
/ 10

CVSS base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

Weaknesses

CVE ID

CVE-2021-29510

GHSA ID

GHSA-5jqp-qgf6-3pvh

Source code

No known source code

Credits

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