CVE-2020-28493

Public Exploit
Regular Expression Denial of Service (ReDoS)

Description

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the `_punctuation_re regex` operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.21%
Vendor Advisory fedoraproject.org Vendor Advisory gentoo.org
Affected: n/a jinja2
Published at:
Updated at:

References

Link Tags
https://snyk.io/vuln/SNYK-PYTHON-JINJA2-1012994 third party advisory exploit
https://github.com/pallets/jinja/blob/ab81fd9c277900c85da0c322a2ff9d68a235b2e6/src/jinja2/utils.py%23L20 broken link
https://github.com/pallets/jinja/pull/1343 third party advisory patch
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVAKCOO7VBVUBM3Q6CBBTPBFNP5NDXF4/ vendor advisory
https://security.gentoo.org/glsa/202107-19 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-28493?
CVE-2020-28493 has been scored as a medium severity vulnerability.
How to fix CVE-2020-28493?
To fix CVE-2020-28493, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2020-28493 being actively exploited in the wild?
It is possible that CVE-2020-28493 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-28493?
CVE-2020-28493 affects n/a jinja2.
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