symfony: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2024-50340 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in symfony, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected symfony versions: < 5.4.46; >= 6.0.0, < 6.4.14; >= 7.0.0, < 7.1.7. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 61.8% chance of exploitation within 30 days, which is in the top 0.81% of all scored CVEs.
Exploitation in the next 30 days is more likely than not, according to EPSS.
What to do
- Update symfony to 5.4.46 or 6.4.14 or 7.1.7, whichever matches your release line, 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.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Symfony | symfony | < 5.4.46; >= 6.0.0, < 6.4.14; >= 7.0.0, < 7.1.7 | Not stated |
| Sensiolabs | symfony | before 5.4.46; 6.0.0 up to, but not including, 6.4.14; 7.0.0 up to, but not including, 7.1.7 | 5.4.46, 6.4.14, 7.1.7 |
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
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. Scored by CNA (github.com).
Official description
symfony/runtime is a module for the Symphony PHP framework which enables decoupling PHP applications from global state. When the `register_argv_argc` php directive is set to `on` , and users call any URL with a special crafted query string, they are able to change the environment or debug mode used by the kernel when handling the request. As of versions 5.4.46, 6.4.14, and 7.1.7 the `SymfonyRuntime` now ignores the `argv` values for non-SAPI PHP runtimes. All users are advised to upgrade. There are no known workarounds for this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in symfony
- 8.6 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
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