CyberSecBulletin
CVE-2024-28861NVD status: Analyzed

symfony1: Deserialization of Untrusted Data

CVE-2024-28861 is a critical-severity deserialization of untrusted data vulnerability in symfony1 from FriendsOfSymfony1, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected symfony1 versions: >= 1.1.0, < 1.5.19. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.55% chance of exploitation within 30 days, higher than 75% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update fosuserbundle to 1.5.19 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.

Affected products and versions

VendorProductAffected versionsFixed in
FriendsOfSymfony1symfony1>= 1.1.0, < 1.5.19Not stated
Friends Of Symfony Projectfosuserbundle1.1.0 up to, but not including, 1.5.191.5.19

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
NoneNo action by a victim is required.
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:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).

Official description

Symfony 1 is a community-driven fork of the 1.x branch of Symfony, a PHP framework for web projects. Starting in version 1.1.0 and prior to version 1.5.19, Symfony 1 has a gadget chain due to dangerous deserialization in `sfNamespacedParameterHolder` class that would enable an attacker to get remote code execution if a developer deserializes user input in their project. Version 1.5.19 contains a patch for the issue.

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

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

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

Other vulnerabilities in symfony1

All symfony1 vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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