CVE-2021-43307

semver-regex <= 3.1.3 and 4.0.0-4.0.3 - Regular Expression Denial of Service (ReDoS)

2022-05-13 00:00

Strategic Overview

Status: Patched in 1.0.5
Affected Plugin: Insert Special Characters
Affected Version: <= 1.0.4
CVSS: 7.5High
Weakness type: CWE-1333 · Inefficient Regular Expression Complexity
CVE: CVE-2021-43307

View all Insert Special Characters vulnerabilities

At a glance

CVE-2021-43307 is a high-severity Inefficient Regular Expression Complexity vulnerability in the Insert Special Characters WordPress plugin, affecting versions <= 1.0.4. It carries a CVSS score of 7.5 (reachable over the network; low attack complexity; high availability impact). Exploitation requires no authentication. The issue is fixed in version 1.0.5; sites on affected versions should update now. Disclosed May 2022.

Vulnerability Overview

An exponential ReDoS (Regular Expression Denial of Service) can be triggered in the semver-regex npm package, when an attacker is able to supply arbitrary input to the test() method. Some WordPress plugins and themes use this dependency though that doesn’t necessarily mean the plugin itself is vulnerable to exploitation.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on availability.

CWE-1333: Inefficient Regular Expression Complexity

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

Remediation

Update to version 1.0.5, or a newer patched version

How does WordSec protect against this?

The fix is the thing that ends this: Insert Special Characters 1.0.5 closes this, and updating the plugin is the step that ends it.

Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-43307 https://www.wordfence.com/threat-intel/vulnerabilities/id/e78c539c-5b72-4043-aa5a-6234913364ac https://nvd.nist.gov/vuln/detail/CVE-2021-43307

Related records

Same weakness class

7.5ansi-regex <3.0.1 >=4.0.0 <4.1.1 >=5.0.0 <5.0.1 >=6.0.0 <6.0.1

Other vulnerabilities in Insert Special Characters

CVSS Vector

7.5

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh

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