Security readout for executives and security teams
Plain-English summary
This flaw can let a specially crafted Addressable URI template consume excessive CPU when the application matches it against a URI. The business impact is service slowdown or denial of service, not data theft. Risk is concentrated in Ruby applications using Addressable templates from untrusted or externally influenced input.
Executive priority
Prioritize remediation for Ruby services where external input can influence URI templates. This is an availability risk with high CVSS severity, but current sources do not show known active exploitation. Patch affected dependencies during the next urgent maintenance cycle, faster for exposed services.
Technical view
CVE-2021-32740 is CWE-400 uncontrolled resource consumption in Addressable versions after 2.3.0 through 2.7.0. The URI template implementation can trigger catastrophic backtracking during template matching. Addressable parsing-only usage is not affected. The issue is fixed in Addressable 2.8.0.
Likely exposure
Exposure is likely where Ruby applications depend on Addressable >2.3.0 and <=2.7.0 and create Template objects from untrusted sources. Typical usage may not do this, and applications using only Addressable parsing capabilities are described as unaffected.
Exploitation context
The source bundle does not show CISA KEV listing or public active exploitation evidence. CVSS rates it network-accessible, low complexity, unauthenticated, and availability-impacting. Treat reachable untrusted template matching as the meaningful exposure condition.
Researcher notes
Scope is narrower than all Addressable usage: the advisory names URI template matching, not general parsing. Affected versions are after 2.3.0 through 2.7.0, with the patch in 2.8.0. Evidence is sufficient for version and feature-level triage.
Mitigation direction
- Upgrade Addressable to version 2.8.0 or later.
- Only create Template objects from trusted, validated sources.
- Prioritize internet-facing services where template matching can be externally influenced.
- Check downstream vendor guidance for packaged Addressable versions.
- Avoid accepting raw URI templates from users without validation.
Validation and detection
- Review dependency manifests and lockfiles for Addressable versions.
- Identify code paths that instantiate Addressable Template objects.
- Confirm whether template input can come from users or external systems.
- Verify deployed environments run Addressable 2.8.0 or a vendor-fixed build.
- Document parsing-only usage separately from template usage.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-400: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-32740 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/sporkmonger/addressable/security/advisories/GHSA-jxhc-q857-3j6gCVE reference · x_refsource_CONFIRM
- https://github.com/sporkmonger/addressable/commit/0d8a3127e35886ce9284810a7f2438bff6b43cbcCVE reference · x_refsource_MISC
- FEDORA-2021-5d14763df8CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-e9fc035565CVE reference · vendor-advisory, x_refsource_FEDORA
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.