youkefu: Improper Restriction of XML External Entity Reference
CVE-2025-3241 is a critical-severity improper restriction of XML external entity reference vulnerability in youkefu from Zhangyanbo2007, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected youkefu versions: 4.0; 4.1; 4.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.66% chance of exploitation within 30 days, higher than 52% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of youkefu you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Zhangyanbo2007 | youkefu | 4.0; 4.1; 4.2 | 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
- NoneNo account or login is needed.
- 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:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.3 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 6.3 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 2.0 | 6.5 | Medium | CNA (vuldb.com) |
Official description
A vulnerability, which was classified as problematic, was found in zhangyanbo2007 youkefu up to 4.2.0. This affects an unknown part of the file src/main/java/com/ukefu/webim/web/handler/admin/callcenter/CallCenterRouterController.java of the component XML Document Handler. The manipulation of the argument routercontent leads to xml external entity reference. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of XML External Entity Reference
The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.
How developers prevent this class of flaw
- Many XML parsers and validators can be configured to disable external entity expansion.
More Improper Restriction of XML External Entity Reference vulnerabilities (CWE-611)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vuldb.com/?id.303267Third Party Advisory, VDB Entry
- vuldb.com/?submit.547585Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- github.com/askqiu/cve/blob/main/README.mdExploit, Third Party Advisory
Other references
- vuldb.com/?ctiid.303267Permissions Required, VDB Entry
Other vulnerabilities in youkefu
- 8.3 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
Recent Improper Restriction of XML External Entity Reference vulnerabilities
- 7.7 High severity
- 7.1 High severity
- 9.8 Critical severity
- 7.1 High severity
- 8.2 High severity
- 7.1 High severity
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