geoserver: Improper Neutralization of Special Elements used in an Expression Language Statement
CVE-2022-24847 is a high-severity improper neutralization of special elements used in an expression language statement vulnerability in geoserver, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected geoserver versions: >= 2.20.0, < 2.20.4; < 2.19.6. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.56% chance of exploitation within 30 days, higher than 76% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of geoserver you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
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
- HighAdministrator-level access is required first.
- 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:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.2 | High | CNA (github.com) |
| CVSS 3.1 | 7.2 | High | NVD |
| CVSS 2.0 | 6.5 | Medium | NVD |
Official description
GeoServer is an open source software server written in Java that allows users to share and edit geospatial data. The GeoServer security mechanism can perform an unchecked JNDI lookup, which in turn can be used to perform class deserialization and result in arbitrary code execution. The same can happen while configuring data stores with data sources located in JNDI, or while setting up the disk quota mechanism. In order to perform any of the above changes, the attack needs to have obtained admin rights and use either the GeoServer GUI, or its REST API. The lookups are going to be restricted in GeoServer 2.21.0, 2.20.4, 1.19.6. Users unable to upgrade should restrict access to the `geoserver/web` and `geoserver/rest` via a firewall and ensure that the GeoWebCache is not remotely accessible.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an Expression Language Statement
The product constructs all or part of an expression language (EL) statement in a framework such as a Java Server Page (JSP) using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended EL statement before it is executed.
How developers prevent this class of flaw
- Avoid adding user-controlled data into an expression interpreter when possible.
- If user-controlled data must be added to an expression interpreter, one or more of the following should be performed: Validate that the user input will not evaluate as an expression Encode the user input in a way that ensures it is not evaluated as an expression
- The framework or tooling might allow the developer to disable or deactivate the processing of EL expressions, such as setting the isELIgnored attribute for a JSP page to true.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/geoserver/geoserver/security/advisories/GHSA-4pm3-f52j-8gghMitigation, Third Party Advisory
Other vulnerabilities in geoserver
- 9.8 Critical severity
- 9.1 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.2 High severity
- 8.2 High severity
Recent Improper Neutralization of Special Elements used in an Expression Language Statement vulnerabilities
- 7.2 High severity
- 9.8 Critical severity
- 10.0 Critical severity
- 9.0 Critical severity
- 10.0 Critical severity
Apache Log4j2 Remote Code Execution Exploited
- 9.8 Critical severity
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