GHSA-c89f-8g7g-59wj CVE-2025-68614
LibreNMS Alert Rule API Cross-Site Scripting Vulnerability
- Severity
- 4.3 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 3.88%
- Chance of exploitation in the next 30 days. Higher than 90.23% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- Fix
25.12.0- Upgrade librenms/librenms to this version or later
Description
Please find POC file here https://trendmicro-my.sharepoint.com/:u:/p/kholoud_altookhy/IQCfcnOE5ykQSb6Fm-HFI872AZ_zeIJxU-3aDk0jh_eX_NE?e=zkN76d
ZDI-CAN-28575: LibreNMS Alert Rule API Cross-Site Scripting Vulnerability
-- CVSS -----------------------------------------
4.3: AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L
-- ABSTRACT -------------------------------------
Trend Micro's Zero Day Initiative has identified a vulnerability affecting the following products: LibreNMS - LibreNMS
-- VULNERABILITY DETAILS ------------------------
- Version tested: 25.10.0
- Installer file: NA
- Platform tested: NA
Analysis
LibreNMS Alert Rule API Stored Cross-Site Scripting
Overview
Alert rules can be created or updated via LibreNMS API. The alert rule name is not properly sanitized, and can be used to inject HTML code.
Affected versions
The latest version at the time of writing (25.10.0) is vulnerable.
Root cause
When an alert rule is created or updated via the API, function add_edit_rule() in includes/html/api_functions.inc.php is called to add/update the entry in the database. When an alert rule is created via the web interface, HTML tags are stripped from the rule name, however this is not the case when using the API.
As such, it is possible to create an alert rule where the name is:
<script>alert(1)</script>
Later, when a victim browses to the Alerts > Alert Rule page, PHP script\xc2\xa0includes/html/print-alert/rules.php\xc2\xa0is called. It notably includes the file\xc2\xa0includes/html/modal/alert_rule_list.inc.php, which returns HTML code for a modal window that searches alert rules.
The modal window includes an HTML table with all rules, including their name, and an inline JavaScript that calls the\xc2\xa0bootgrid()\xc2\xa0function (http://www.jquery-bootgrid.com/) for styling and enhancing the table.
alert_rule.list.inc.php sanitizes the rule name with the function e() before including it in the table, which XML encodes all special characters. However the\xc2\xa0bootgrid()\xc2\xa0function rewrites the table cells content when enhancing the table, and as a side effect, XML character references are decoded. After the script updated the table, the browser now interprets the payload as HTML tags and includes the code to the DOM.
Detection guidance
- inspect HTTP POST and PUT requests to a Request-URI that includes the string\xc2\xa0
/api/v0/rules - check if the\xc2\xa0
name\xc2\xa0JSON value includes a<character
PoC
The proof-of-concept can be run as such:
python3 poc.py ip_addr -T <token>
-- CREDIT --------------------------------------- This vulnerability was discovered by: Simon Humbert of Trend Research of Trend Micro
-- FURTHER DETAILS ------------------------------
Supporting files:
If supporting files were contained with this report they are provided within a password protected ZIP file. The password is the ZDI candidate number in the form: ZDI-CAN-XXXX where XXXX is the ID number.
Please confirm receipt of this report. We expect all vendors to remediate ZDI vulnerabilities within 120 days of the reported date. If you are ready to release a patch at any point leading up to the deadline, please coordinate with us so that we may release our advisory detailing the issue. If the 120-day deadline is reached and no patch has been made available we will release a limited public advisory with our own mitigations, so that the public can protect themselves in the absence of a patch. Please keep us updated regarding the status of this issue and feel free to contact us at any time:
Zero Day Initiative zdi-disclosures@trendmicro.com
The PGP key used for all ZDI vendor communications is available from:
http://www.zerodayinitiative.com/documents/disclosures-pgp-key.asc
-- INFORMATION ABOUT THE ZDI -------------------- Established by TippingPoint and acquired by Trend Micro, the Zero Day Initiative (ZDI) neither re-sells vulnerability details nor exploit code. Instead, upon notifying the affected product vendor, the ZDI provides its Trend Micro TippingPoint customers with zero day protection through its intrusion prevention technology. Explicit details regarding the specifics of the vulnerability are not exposed to any parties until an official vendor patch is publicly available.
Please contact us for further details or refer to:
http://www.zerodayinitiative.com
-- DISCLOSURE POLICY ----------------------------
Our vulnerability disclosure policy is available online at:
http://www.zerodayinitiative.com/advisories/disclosure_policy/
Affected versions
Packagist
| Package | Vulnerable | Fixed in |
|---|---|---|
| librenms/librenms | < 25.12.0 |
25.12.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
librenms/librenms Packagist → 25.12.0
- composer
composer require librenms/librenms:^25.12.0
Severity breakdown
CVSS 3.1 4.3
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Weakness
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
How to prevent it
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
- Implementation, Architecture and Design: Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies. For any data that will be output to another web page, especially any data that was received from external inputs, use the appropriate encoding on all non-alphanumeric characters. Parts of the same output document may require different encodings, which will vary depending on whether the output is in the: HTML body Element attributes (such as src="XYZ") URIs JavaScript sections Cascading Style Sheets and style property etc. Note that HTML Entity Encoding is only appropriate for the HTML body. Consult the XSS Prevention Cheat Sheet [REF-724] for more details on the types of encoding and escaping that are needed.
- Architecture and Design, Implementation: Understand all the potential areas where untrusted inputs can enter your software: 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.
- Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Architecture and Design: If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
- Implementation: Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component. The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.
- Implementation: With Struts, write all data from form beans with the bean's filter attribute set to true.
- Implementation: To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. When dynamically constructing web pages, use stringent allowlists that limit the character set based on the expected value of the parameter in the request. All input should be validated and cleansed, not just parameters that the user is supposed to specify, but all data in the request, including hidden fields, cookies, headers, the URL itself, and so forth. A common mistake that leads to continuing XSS vulnerabilities is to validate only fields that are expected to be redisplayed by the site. It is common to see data from the request that is reflected by the application server or the application that the development team did not anticipate. Also, a field that is not currently reflected may be used by a future developer. Therefore, validating ALL parts of the HTTP request is recommended. Note that proper output encoding, escaping, and quoting is the most ef
- Architecture and Design: When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
- Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
- Operation, Implementation: When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-7w8c-qgxg-m7jx LibreNMS — Stored XSS via SNMP/Syslog Data in Legacy Templates | High | Also affects librenms/librenms |
| GHSA-7gww-x7fh-jf9j LibreNMS: SSRF-driven stored XSS via Oxidized API response fields in device showconfig page | Critical | Also affects librenms/librenms |
| GHSA-7cj5-v4pp-v632 LibreNMS: Stored XSS via graph_descr admin config settings echoed without escaping to all authenticated users | Medium | Also affects librenms/librenms |
| GHSA-jf24-8g2h-2wg7 LibreNMS Vulnerable to Remote Code Execution via AboutController | High | Also affects librenms/librenms |
| GHSA-c9fv-cgmm-2wg7 LibreNMS Vulnerable to Remote Code Execution by Signal Alert Transportation module | High | Also affects librenms/librenms |
| GHSA-jmqm-f8q4-v7wx LibreNMS: Reflected XSS via Proxmox instance/vmid GET parameters injected into document.title JavaScript assignment | Medium | Also affects librenms/librenms |
| GHSA-5gm9-622f-qcg5 LibreNMS: Cross-Site Scripting in ShowConfigController | Medium | Also affects librenms/librenms |
| GHSA-pr3g-phhr-h8fh LibreNMS is Vulnerable to Remote Code Execution by Arbitrary File Write | High | Also affects librenms/librenms |
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor