iSTAR Ultra: Download of Code Without Integrity Check
CVE-2025-53696 is a critical-severity download of code without integrity check vulnerability in iSTAR Ultra from Johnson Controls, with a CVSS 4.0 base score of 9.3 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. Affected iSTAR Ultra versions: 6.9.2 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.1% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of iSTAR Ultra you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Johnson Controls | iSTAR Ultra | 6.9.2 and earlier | 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
- LocalThe attacker needs local access or must trick a user into running something.
- 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:L/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 (dragos.com).
Official description
iSTAR Ultra performs a firmware verification on boot, however the verification does not inspect certain portions of the firmware. These firmware parts may contain malicious code. Tested up to firmware 6.9.2, later firmwares are also possibly affected.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Download of Code Without Integrity Check
The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.
How developers prevent this class of flaw
- Perform proper forward and reverse DNS lookups to detect DNS spoofing.
- Encrypt the code with a reliable encryption scheme before transmitting.
- Run your code using the lowest privileges that are required to accomplish the necessary tasks. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
More Download of Code Without Integrity Check vulnerabilities (CWE-494)
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
Other vulnerabilities in iSTAR Ultra
- 7.0 High severity
- 7.0 High severity
- 8.4 High severity
- 8.7 High severity
- 9.4 Critical severity
- 9.8 Critical severity
Recent Download of Code Without Integrity Check vulnerabilities
- 8.8 High severity
- 9.3 Critical severity
- 7.5 High severity
- 8.2 High severity
- 9.3 Critical severity
- 7.3 High severity
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