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GHSA-pjv5-vv93-p648 CVE-2019-19709

Possible to circumvent title-blacklist

Medium Packagist
Severity
6.1 / 10
Medium · CVSS 3.1
Exploit chance (EPSS)
1.56%
Chance of exploitation in the next 30 days. Higher than 75.29% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-601 URL Redirection to Untrusted Site ('Open Redirect')
Fix
1.31.6
Upgrade mediawiki/core to this version or later

Description

MediaWiki through 1.33.1 allows attackers to bypass the Title_blacklist protection mechanism by starting with an arbitrary title, establishing a non-resolvable redirect for the associated page, and using redirect=1 in the action API when editing that page.

Affected versions

Packagist

PackageVulnerableFixed in
mediawiki/core
>= 1.31.0, < 1.31.6
1.31.6
mediawiki/core
>= 1.32.0, < 1.32.6
1.32.6
mediawiki/core
>= 1.33.0, < 1.33.2
1.33.2
mediawiki/core
>= 1.33.99, < 1.34.0
1.34.0

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

mediawiki/core Packagist → 1.31.6

composer
composer require mediawiki/core:^1.31.6

Severity breakdown

CVSS 3.1 6.1

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

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

Weakness

CWE-601: URL Redirection to Untrusted Site ('Open Redirect')

The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.

How to prevent it
  • Implementation: 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. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. Use a list of approved URLs or domains to be used for redirection.
  • 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: 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 [REF-45] provide this capability.
  • Architecture and Design: Ensure that no externally-supplied requests are honored by requiring that all redirect requests include a unique nonce generated by the application [REF-483]. Be sure that the nonce is not predictable (CWE-330).
  • Architecture and Design, Implementation: Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls. Many open redirect problems occur because the programmer assumed that certain inputs could not be modified, such as cookies and hidden form fields.
  • Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-w5fx-cx7f-6vr9
MediaWiki Denial of Service vulnerability
High Also affects mediawiki/core
GHSA-5vj8-g3qg-4qh6
X-Forwarded-For header allows brute-forcing autoblocked IP addresses
Critical Also affects mediawiki/core
GHSA-c8wv-qwwc-6j73
MediaWiki allows a denial of service
Medium Also affects mediawiki/core
GHSA-rqvj-fc2x-99q6
OATHAuth extension in MediaWiki is not implementing rate limit
High Also affects mediawiki/core
GHSA-c4rj-wrmq-52rj
MediaWiki Special:UserRights exposes the existence of hidden users
Medium Also affects mediawiki/core
GHSA-h8qx-mj6v-2934
MediaWiki Cross-site Scripting (XSS) vulnerability
Medium Also affects mediawiki/core
GHSA-4vr7-m8p8-434h
MediaWiki Cross-site Scripting (XSS) vulnerability
Medium Also affects mediawiki/core
GHSA-2f58-vf6g-6p8x
MediaWiki Cross-site Scripting (XSS) vulnerability
Medium Also affects mediawiki/core
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