VulnerabilityPublished 23 Sep 2025

CVE-2025-59547: dnnsoftware Dnn.Platform · Improper Handling of Unicode Encoding

Affects dnnsoftware Dnn.PlatformSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 10.1.0 when convenient.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 10.1.0

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade dnnsoftware Dnn.Platform to 10.1.0.

Affected software

Product	Affected	Fixed in
dnnsoftware Dnn.Platform	Affected <10.1.0	Fixed in 10.1.0

AI-suggested

Upgrade Dnn.Platform to version 10.1.0 or later immediately, as this version contains the official patch addressing the Unicode filename sanitization issue.
Restrict access to the CKEditor file upload endpoint by implementing network-level controls such as IP whitelisting, VPN access, or web application firewall (WAF) rules to limit exposure to trusted users only.
Implement strict input validation and sanitization on file uploads, ensuring filenames do not contain unexpected Unicode characters or path traversal sequences.
Monitor web server logs for unusual file upload requests containing Unicode or suspicious patterns that could indicate probing attempts.
Conduct internal network segmentation and hardening to reduce the impact of any internal reconnaissance, ensuring that sensitive internal endpoints are not directly accessible from web-facing servers.
Employ runtime application self-protection (RASP) or intrusion detection systems (IDS) to detect and block exploitation attempts targeting the file upload functionality.
Educate development and operations teams about secure handling of Unicode and input sanitization best practices to prevent similar vulnerabilities in custom or third-party components.

Description

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.1.0, the CKEditor file upload endpoint has insufficient sanitization for filenames allowing probing network endpoints. A specially crafted request can be made to upload a file with Unicode characters, which would be translated into a path that could expose resources in the internal network of the hosted site. This issue has been patched in version 10.1.0.

Impact

For European organizations using Dnn.Platform versions earlier than 10.1.0, this vulnerability poses a risk of internal network reconnaissance and potential information disclosure. Attackers exploiting this flaw could map internal network endpoints, gaining insights into network architecture, services, or sensitive internal resources. This could be a stepping stone for more advanced attacks such as lateral movement, targeted exploitation of internal services, or data exfiltration. The impact is particularly relevant for organizations hosting sensitive or critical infrastructure websites on Dnn.Platform, including government agencies, healthcare providers, financial institutions, and enterprises with internal web portals. Since the vulnerability does not directly allow code execution or data modification, the immediate impact is limited to confidentiality breaches. However, the exposure of internal network details can significantly increase the attack surface and risk profile. European organizations with strict data protection regulations (e.g., GDPR) must consider the potential compliance implications of any unauthorized internal information disclosure. Additionally, organizations with segmented networks relying on obscurity for internal resource protection may find this vulnerability undermines that security assumption.

CWE-176Improper Handling of Unicode Encoding (opens in a new tab)
Variant weakness
The product does not properly handle when an input contains Unicode encoding.
Architecture and Design · Input Validation
Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Unvalidated Redirects and Forwards (opens in a new tab)
XML Security (opens in a new tab)
XML External Entity Prevention (opens in a new tab)
File Upload (opens in a new tab)
Input Validation (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.2 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
Using Unicode Encoding to Bypass Validation Logic (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/dnnsoftware/Dnn.Platform/security/advisories/GHSA-cgqj-mw4m-v7hp (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 23 Sep 2025, 18:03 UTC

WeaknessesCWE-176

Technical details

References

Community reviews

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