Lucee: Improper Control of Generation of Code
CVE-2025-34074 is a critical-severity improper control of generation of code vulnerability in Lucee from Lucee Association Switzerland, with a CVSS 4.0 base score of 9.4 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected Lucee versions: 5.0; 6.0; All versions with scheduled task functionality. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.2% chance of exploitation within 30 days, higher than 83% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Lucee you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Lucee Association Switzerland | Lucee | 5.0; 6.0; All versions with scheduled task functionality | Not stated |
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.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- HighSerious loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- HighSerious loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- HighSerious loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (vulncheck.com).
Official description
An authenticated remote code execution vulnerability exists in Lucee’s administrative interface due to insecure design in the scheduled task functionality. An administrator with access to /lucee/admin/web.cfm can configure a scheduled job to retrieve a remote .cfm file from an attacker-controlled server, which is written to the Lucee webroot and executed with the privileges of the Lucee service account. Because Lucee does not enforce integrity checks, path restrictions, or execution controls for scheduled task fetches, this feature can be abused to achieve arbitrary code execution. This issue is distinct from CVE-2024-55354.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Improper Control of Generation of Code vulnerabilities
- 7.8 High severity
- 9.1 Critical severity
- 8.8 High severity
- 8.6 High severity
- 9.8 Critical severity
- 7.8 High severity
Spotted an error? Tell us.