mailcow-dockerized: URL Redirection to Untrusted Site
CVE-2025-25198 is a high-severity URL redirection to untrusted site vulnerability in mailcow-dockerized from Mailcow, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected mailcow-dockerized versions: < 2025-01a. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.12% chance of exploitation within 30 days, higher than 67% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Mailcow to 2025-01a or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Mailcow | mailcow-dockerized | < 2025-01a | Not stated |
| Mailcow | Mailcow | before 2025-01a | 2025-01a |
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
- RequiredA user must take an action such as opening a file or link.
- 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:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.1 | High | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
mailcow: dockerized is an open source groupware/email suite based on docker. Prior to version 2025-01a, a vulnerability in mailcow's password reset functionality allows an attacker to manipulate the `Host HTTP` header to generate a password reset link pointing to an attacker-controlled domain. This can lead to account takeover if a user clicks the poisoned link. Version 2025-01a contains a patch. As a workaround, deactivate the password reset functionality by clearing `Notification email sender` and `Notification email subject` under System -> Configuration -> Options -> Password Settings.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: URL Redirection to Untrusted Site
The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.
How developers prevent this class of flaw
- 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.
- 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. For example, ID 1 could map to /login.asp and ID 2 could map to http://www.example.com/. Features such as the ESAPI AccessReferenceMap provide this capability.
- Ensure that no externally-supplied requests are honored by requiring that all redirect requests include a unique nonce generated by the application. Be sure that the nonce is not predictable (CWE-330).
More URL Redirection to Untrusted Site vulnerabilities (CWE-601)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in mailcow-dockerized
- 9.1 Critical severity
- 7.4 High severity
- 7.0 High severity
- 8.9 High severity
- 9.3 Critical severity
- 7.2 High severity
Recent URL Redirection to Untrusted Site vulnerabilities
- 7.4 High severity
- 7.1 High severity
- 8.7 High severity
- 7.2 High severity
- 8.8 High severity
- 8.8 High severity
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