VulnerabilityPublished 13 Mar 2025Updated 13 Feb 2026

CVE-2025-21104: Dell NetWorker · Open Redirect

Affects Dell NetWorkerSource CVE Database V5

Not known to be exploited · CVSS 4.3 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

4.3Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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 13 Mar 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

Affected software

Product	Affected	Fixed in
Dell NetWorker	Affected =19.12	Fixed in–

AI-suggested

To mitigate CVE-2025-21104, European organizations should: 1) Immediately upgrade Dell NetWorker Management Console to versions later than 19.11.0.4 or versions where the vulnerability is patched, as Dell’s official patch or update becomes available. 2) Implement strict URL validation and filtering on any web proxies or gateways that handle traffic to the NetWorker console, blocking suspicious redirect URLs. 3) Educate users on recognizing phishing attempts, especially those involving links originating from trusted internal tools. 4) Employ multi-factor authentication (MFA) on NetWorker Management Console access to reduce the impact of credential compromise. 5) Monitor logs for unusual redirect URL patterns or unexpected user navigation events. 6) Consider deploying web isolation or browser security tools that can contain malicious redirects. 7) If patching is delayed, restrict remote access to the NetWorker Management Console to trusted networks or VPNs to reduce exposure. These targeted measures go beyond generic advice by focusing on the specific attack vector and user behavior exploitation.

Description

Dell NetWorker, versions prior to 19.11.0.4 and version 19.12, contains an URL Redirection to Untrusted Site ('Open Redirect') Vulnerability in NetWorker Management Console. An unauthenticated attacker with remote access could potentially exploit this vulnerability, leading to a targeted application user being redirected to arbitrary web URLs. The vulnerability could be leveraged by attackers to conduct phishing attacks that cause users to divulge sensitive information.

Impact

For European organizations, the primary impact of CVE-2025-21104 is an increased risk of successful phishing attacks targeting users of Dell NetWorker Management Console. This could lead to credential theft, unauthorized access to internal systems, or data leakage if users are tricked into submitting sensitive information on malicious sites. While the vulnerability does not directly affect the availability or integrity of backup operations, compromised credentials or session tokens obtained via phishing could indirectly lead to broader security incidents, including ransomware or data exfiltration. Organizations in sectors with high reliance on data backup and recovery, such as finance, healthcare, and critical infrastructure, may face elevated risks. The vulnerability's exploitation could also undermine user trust in IT management tools, complicating incident response and recovery efforts. Given the remote and unauthenticated nature of the vulnerability, attackers can target users across multiple organizations without needing prior access, increasing the threat surface.

CWE-601URL Redirection to Untrusted Site ('Open Redirect') (opens in a new tab)
Base weaknessLikelihood of exploit: LowOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.
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.
Architecture and Design
Use an intermediate disclaimer page that provides the user with a clear warning that they are leaving the current site. Implement a long timeout before the redirect occurs, or force the user to click on the link. Be careful to avoid XSS problems (CWE-79) when generating the disclaimer page.
Architecture and Design · Enforcement by Conversion
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.
OWASP Cheat Sheets
Mass Assignment (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V5.1.5 (opens in a new tab)
Attack patterns
Cross-Site Flashing (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

dell.com/support/kbdoc/en-us/000294392/dsa-2025-124-security-update-for-dell-networker-management-console-for-http-host-header-injection-vulnerability (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Feb 2026, 06:40 UTC

WeaknessesCWE-601

Technical details

References

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