CVE-2021-32740

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Exploit odds

2.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-07-06 15:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:53 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.1% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-07-06 15:15 UTC

Last modified

2026-06-17 03:53 UTC

Exploit probability

2.1% · EPSS, next 30 days

Weakness

CWE-400 · Uncontrolled resource consumption

Record status

Modified

Affected

• Addressable Project Addressable < 2.8.0
• Fedoraproject Fedora 33
• Fedoraproject Fedora 34

Attack profile CVSS 3.1 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-32740.md and follow it. Check whether this project is affected by CVE-2021-32740. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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