astro-shield: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2024-29896 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in astro-shield from KindSpells, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 1.3.0 as the first without the flaw, so updating astro-shield to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.59% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update astro-shield to 1.3.0 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 |
|---|---|---|---|
| KindSpells | astro-shield | = 1.2.0; 1.2.0 up to, but not including, 1.3.0 | 1.3.0 |
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
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CNA (github.com).
Official description
Astro-Shield is a library to compute the subresource integrity hashes for your JS scripts and CSS stylesheets. When automated CSP headers generation for SSR content is enabled and the web application serves content that can be partially controlled by external users, then it is possible that the CSP headers generation feature might be "allow-listing" malicious injected resources like inlined JS, or references to external malicious scripts. The fix is available in version 1.3.0.
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 astro-shield
- 7.5 High severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 9.0 Critical severity
- 8.1 High severity
- 9.1 Critical severity
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
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