Powershell Extension: Unrestricted Upload of File with Dangerous Type
CVE-2025-34511 is a high-severity unrestricted upload of file with dangerous type vulnerability in Powershell Extension from Sitecore, 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 Powershell Extension versions: 7.0 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 32.4% chance of exploitation within 30 days, which is in the top 1.65% of all scored CVEs.
EPSS places it among the vulnerabilities most likely to be exploited soon.
What to do
- Update Experience Platform to 10.4 or a later version.
- Read the advisory on support.sitecore.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Sitecore | Powershell Extension | 7.0 and earlier | Not stated |
| Sitecore | Experience Commerce | 9.0 through 10.4 | Not stated |
| Sitecore | Experience Manager | 9.0 through 10.4 | Not stated |
| Sitecore | Experience Platform | 9.0 up to, but not including, 10.4; 10.4 | 10.4 |
| Sitecore | Managed Cloud | Not specified in the record | 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.
- 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 CNA (vulncheck.com).
Official description
Sitecore PowerShell Extensions, an add-on to Sitecore Experience Manager (XM) and Experience Platform (XP), through version 7.0 is vulnerable to an unrestricted file upload issue. A remote, authenticated attacker can upload arbitrary files to the server using crafted HTTP requests, resulting in remote code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Unrestricted Upload of File with Dangerous Type
The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
How developers prevent this class of flaw
- Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
- 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.
- Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.
More Unrestricted Upload of File with Dangerous Type vulnerabilities (CWE-434)
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
Technical write-ups (may include proof of concept)
- labs.watchtowr.com/is-b-for-backdoor-pre-auth-rce-chain-in-sitecore-experience-platform/Exploit, Third Party Advisory
Recent Unrestricted Upload of File with Dangerous Type vulnerabilities
- 7.5 High severity
- 10.0 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
- 9.9 Critical severity
- 9.9 Critical severity
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