CVE-2022-39315 — cms
MEDIUMCVE-2022-39315 is a medium-severity (CVSS 6.5) CWE-204 vulnerability in getkirby/cms. A fix is available for getkirby/cms — see the affected versions and patch details below.
Kirby CMS vulnerable to user enumeration in the brute force protection
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-39315.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
getkirby/cms🐘getkirby/cms🐘getkirby/cms🐘getkirby/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
TL;DR
This vulnerability affects all Kirby sites with user accounts (unless Kirby's API and Panel are disabled in the config). It can only be exploited for targeted attacks because the attack does not scale to brute force.
Introduction
User enumeration is a type of vulnerability that allows attackers to confirm which users are registered in a Kirby installation. This information can be abused for social engineering attacks against users of the site or to find out the organizational structure of the company.
User enumeration attacks are performed by entering an existing and a non-existing user into the email address field of the login form. If the system returns a different response or behaves differently depending on whether the user exists, the attacker can enter unknown email addresses and use the different behavior as a clue for the (non-)existing user.
Impact
Kirby comes with a built-in brute force protection. By default, it will prevent further login attempts after 10 failed logins from a single IP address or of a single existing user. After every failed login attempt, Kirby inserts a random delay between one millisecond and two seconds to make automated attacks harder and to avoid leaking whether the user exists. Unfortunately, this random delay was not inserted after the brute force limit was reached.
Because Kirby only tracks failed login attempts per email address for existing users but always tracks failed login attempts per IP address, this behavior could be abused by attackers for user enumeration. For this to work, an attacker would need to create login requests beyond the trials limit (which is 10 by default) from two or more IP addresses. After the trials limit was reached, the login form immediately blocked further requests for existing users, but not for invalid users.
This exploit does not scale to brute force attacks because of the delay during the first 10 requests per user, the faint difference between the responses for valid and invalid users and the fact that code-based logins would send an email for every login attempt, which makes the attack easy to spot. The vulnerability is therefore only relevant for targeted attacks.
Patches
The problem has been patched in Kirby 3.5.8.2, Kirby 3.6.6.2, Kirby 3.7.5.1 and Kirby 3.8.1. Please update to one of these or a later version to fix the vulnerability.
In all of the mentioned releases, we have rewritten the affected code so that the delay is also inserted after the brute force limit is reached.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getkirby/cms | all versions | 3.5.8.2composer require getkirby/cms:^3.5.8.2 |
| 🐘Packagist | getkirby/cms | ≥ 3.6.0&&< 3.6.6.2 | 3.6.6.2composer require getkirby/cms:^3.6.6.2 |
| 🐘Packagist | getkirby/cms | ≥ 3.7.0&&< 3.7.5.1 | 3.7.5.1composer require getkirby/cms:^3.7.5.1 |
| 🐘Packagist | getkirby/cms | ≥ 3.8.0&&< 3.8.1 | 3.8.1composer require getkirby/cms:^3.8.1 |
Affected Products
kirbygetkirbyDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getkirby/cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update getkirby/cms to 3.5.8.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-39315 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2022-39315 in your dependencies?
Find it across Packagist, including transitive dependencies.