Uptime Kuma, a self-hosted monitoring tool, allows an authenticated attacker to install a…
CVE-2023-36821 is a high-severity improper input validation vulnerability in uptime-kuma from Louislam, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected uptime-kuma versions: < 1.22.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.02% chance of exploitation within 30 days, higher than 81% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update uptime-kuma to 1.22.1 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Louislam | uptime-kuma | < 1.22.1 | Not stated |
| Uptime-kuma Project | uptime-kuma | before 1.22.1 | 1.22.1 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
Uptime Kuma, a self-hosted monitoring tool, allows an authenticated attacker to install a maliciously crafted plugin in versions prior to 1.22.1, which may lead to remote code execution. Uptime Kuma allows authenticated users to install plugins from an official list of plugins. This feature is currently disabled in the web interface, but the corresponding API endpoints are still available after login. After downloading a plugin, it's installed by calling `npm install` in the installation directory of the plugin. Because the plugin is not validated against the official list of plugins or installed with `npm install --ignore-scripts`, a maliciously crafted plugin taking advantage of npm scripts can gain remote code execution. Version 1.22.1 contains a patch for this issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Other vulnerabilities in uptime-kuma
- 8.1 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.1 High severity
Recent Improper Input Validation vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 7.8 High severity
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