CVE-2023-39165

Sign-up Sheets <= 2.2.8 - Cross-Site Request Forgery

2023-08-07 00:00

Strategic Overview

Status: Patched in 2.2.9
Affected Plugin: Sign-up Sheets
Affected Version: <= 2.2.8
CVSS: 4.3Medium
Weakness type: CWE-352 · Cross-Site Request Forgery (CSRF)
CVE: CVE-2023-39165

At a glance

CVE-2023-39165 is a medium-severity Cross-Site Request Forgery (CSRF) vulnerability in the Sign-up Sheets WordPress plugin, affecting versions <= 2.2.8. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 2.2.9; sites on affected versions should update now. Disclosed August 2023, reported by Nguyen Xuan Chien.

Vulnerability Overview

The Sign-up Sheets plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.2.8. This is due to missing nonce validation on the maybeProcessReset() and maybeProcessSave() functions. This makes it possible for unauthenticated attackers to save and reset the plugin's settings via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

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.

CWE-352: Cross-Site Request Forgery (CSRF)

Sign-up Sheets <= 2.2.8 carries this weakness at maybeProcessReset(), and reaching it takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.

An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For Sign-up Sheets the fix is 2.2.9: builds <= 2.2.8 are affected, anything from 2.2.9 onward is not.

Remediation

Update to version 2.2.9, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Sign-up Sheets: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Sign-up Sheets 2.2.9 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2023-39165 https://www.wordfence.com/threat-intel/vulnerabilities/id/9999301a-002d-441b-bd66-6b7f4c46a8bf https://nvd.nist.gov/vuln/detail/CVE-2023-39165

Related records

Same weakness class

Other vulnerabilities in Sign-up Sheets

CVSS Vector

4.3

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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