CyberSecBulletin
CVE-2022-39258NVD status: Modified

mailcow-dockerized: URL Redirection to Untrusted Site

CVE-2022-39258 is a high-severity URL redirection to untrusted site vulnerability in mailcow-dockerized from Mailcow, with a CVSS 3.1 base score of 8.2 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: < 2022-09. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.83% chance of exploitation within 30 days, higher than 79% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Mailcow to 2022-09 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. 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

VendorProductAffected versionsFixed in
Mailcowmailcow-dockerized< 2022-09Not stated
MailcowMailcowbefore 2022-092022-09

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
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
LowLimited modification of data is possible.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.1HighCNA (github.com)
CVSS 3.18.2HighNVD

Official description

mailcow is a mailserver suite. A vulnerability innversions prior to 2022-09 allows an attacker to craft a custom Swagger API template to spoof Authorize links. This could redirect a victim to an attacker controller place to steal Swagger authorization credentials or create a phishing page to steal other information. The issue has been fixed with the 2022-09 mailcow Mootember Update. As a workaround, one may delete the Swapper API Documentation from their e-mail server.

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

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in mailcow-dockerized

All mailcow-dockerized vulnerabilities

Recent URL Redirection to Untrusted Site vulnerabilities

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