Security readout for executives and security teams
Plain-English summary
CVE-2021-43306 is a denial-of-service issue in the jquery-validation npm package. If an attacker can feed arbitrary input into the url2 validation method, a crafted value can make regex processing consume excessive CPU, slowing or stopping availability. The bundle rates it medium with CVSS 5.9.
Executive priority
Treat as a targeted availability risk, not a confirmed widespread emergency. Prioritize internet-facing or high-traffic services using jquery-validation, especially where URL fields accept untrusted input. Lack of version detail means teams should verify exposure before escalating remediation broadly.
Technical view
The issue is exponential ReDoS, CWE-1333, in jquery-validation's url2 method. CVSS indicates network reachability, no privileges, no user interaction, high availability impact, and high attack complexity. Affected versions are not specified in the provided CVE data.
Likely exposure
Exposure is likely where applications use jquery-validation and pass attacker-controlled values to url2 validation on a server or availability-sensitive client path. The bundle does not identify specific affected versions, CPEs, or platforms, so dependency inventory is required.
Exploitation context
The CVE is not listed as KEV, and the provided sources do not state active exploitation. Exploitation depends on attacker-controlled input reaching url2 and causing costly regex evaluation; CVSS marks attack complexity high.
Researcher notes
Evidence is limited to the CVE data and JFrog reference in the bundle. No exploit-in-the-wild claim, fixed version, or affected version range is provided here. The key research question is whether attacker-controlled data reaches jquery-validation url2 in an availability-relevant context.
Mitigation direction
- Inventory jquery-validation usage across source code, lockfiles, and deployed builds.
- Check jquery-validation and JFrog guidance for fixed versions or recommended mitigations.
- Avoid passing untrusted arbitrary input to url2 where feasible.
- Apply input length limits before URL validation paths.
- Prioritize availability-sensitive public routes for review.
Validation and detection
- Confirm whether jquery-validation is present in application dependencies.
- Search code paths for use of the url2 validation method.
- Determine whether attacker-controlled input can reach those paths.
- Review runtime monitoring for CPU spikes tied to URL validation.
- Document affected services and remediation status.
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
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-1333: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-43306 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/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:H/PR:N/UI:N/S:U/C:N/I:N/A:H2.23.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.9MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://research.jfrog.com/vulnerabilities/jquery-validation-redos-xray-211348/CVE reference · x_refsource_MISC
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.
Inefficient Regular Expression Complexity
Inefficient Regular Expression Complexity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.