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Regular Expression Denial of Service in Addressable templates

High severity GitHub Reviewed Published Jul 3, 2021 in sporkmonger/addressable • Updated May 4, 2023

Package

bundler addressable (RubyGems)

Affected versions

>= 2.3.0, <= 2.7.0

Patched versions

2.8.0

Description

Impact

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.

Patches

The vulnerability was introduced in version 2.3.0 (previously yanked) and has been present in all subsequent versions up to, and including, 2.7.0. It is fixed in version 2.8.0.

Workarounds

The vulnerability can be avoided by only creating Template objects from trusted sources that have been validated not to produce catastrophic backtracking.

References

For more information

If you have any questions or comments about this advisory:

References

@sporkmonger sporkmonger published to sporkmonger/addressable Jul 3, 2021
Published by the National Vulnerability Database Jul 6, 2021
Reviewed Jul 6, 2021
Published to the GitHub Advisory Database Jul 12, 2021
Last updated May 4, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.252%
(66th percentile)

Weaknesses

CVE ID

CVE-2021-32740

GHSA ID

GHSA-jxhc-q857-3j6g

Source code

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