Resource exhaustion in Palletsprojects Jinja

CVE-2020-28493

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.

Vulnerability class: DoS (Denial of Service)

EPSS: 0.035 (88.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-28493?
CVE-2020-28493 is a medium-severity vulnerability in Palletsprojects Jinja, classified under Uncontrolled Resource Consumption. CVSS score: 5.3/10. Published 2021-02-01.
How severe is CVE-2020-28493?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2020-28493 known to be exploited?
7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.