CyberSecBulletin
CVE-2022-24894NVD status: Analyzed

symfony: Improper Authorization

Published Updated By the CyberSecBulletin desk

CVE-2022-24894 is a high-severity improper authorization vulnerability in symfony, 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 symfony versions: >= 2.0.0, < 4.4.50; >= 5.0.0, < 5.4.20; >= 6.0.0, < 6.0.20, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 4.11% chance of exploitation within 30 days, which is in the top 9.07% of all scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of symfony you run against the affected versions below, and install the vendor's latest release.
  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
Symfonysymfony>= 2.0.0, < 4.4.50; >= 5.0.0, < 5.4.20; >= 6.0.0, < 6.0.20; >= 6.1.0, < 6.1.12; >= 6.2.0, < 6.2.6Not stated

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 systemScoreSeverityScored by
CVSS 3.15.9MediumCNA (github.com)
CVSS 3.18.8HighNVD

Official description

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The Symfony HTTP cache system, acts as a reverse proxy: It caches entire responses (including headers) and returns them to the clients. In a recent change in the `AbstractSessionListener`, the response might contain a `Set-Cookie` header. If the Symfony HTTP cache system is enabled, this response might bill stored and return to the next clients. An attacker can use this vulnerability to retrieve the victim's session. This issue has been patched and is available for branch 4.4.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Authorization

The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.

How developers prevent this class of flaw

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Ensure that you perform access control checks related to your business logic. These checks may be different than the access control checks that you apply to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.

More Improper Authorization vulnerabilities (CWE-285)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in symfony

All symfony vulnerabilities

Recent Improper Authorization vulnerabilities

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