CVE-2021-32740: Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. An uncontrolled resource consumption v...

Description

Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. An uncontrolled resource consumption vulnerability exists after version 2.3.0 through version 2.7.0. Within the URI template implementation in Addressable, a maliciously crafted template may result in uncontrolled resource consumption, leading to denial of service when matched against a URI. In typical usage, templates would not normally be read from untrusted user input, but nonetheless, no previous security advisory for Addressable has cautioned against doing this. Users of the parsing capabilities in Addressable but not the URI template capabilities are unaffected. The vulnerability is patched in version 2.8.0. As a workaround, only create Template objects from trusted sources that have been validated not to produce catastrophic backtracking.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

2.20%

80.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Addressable Project	Addressable	>= 2.3.0, < 2.8.0
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34

References

Timeline

Published: Jul 6, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32740?

Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. An uncontrolled resource consumption vulnerability exists after version 2.3.0 through version 2.7.0. Within the URI template implementation in Addressable, a maliciously crafted template may result in uncontrolled resource consumption, leading to denial of service when matched against a URI. In typical usage, templates would not normally be read from untrusted user input, but nonetheless, no previous security advisory for Addressable has cautioned against doing this. Users of the parsing capabilities in Addressable but not the URI template capabilities are unaffected. The vulnerability is patched in version 2.8.0. As a workaround, only create Template objects from trusted sources that have been validated not to produce catastrophic backtracking.

How severe is CVE-2021-32740?

CVE-2021-32740 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.20% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32740?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.