CyberSecBulletin
CVE-2024-41950NVD status: Deferred

haystack: Improper Neutralization of Special Elements Used in a Template Engine

CVE-2024-41950 is a high-severity improper neutralization of special elements used in a template engine vulnerability in haystack from Deepset-ai, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected haystack versions: < 2.3.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.17% chance of exploitation within 30 days, higher than 68% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update haystack to 2.3.1 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Deepset-aihaystack< 2.3.1Not stated
Deepsethaystackbefore 2.3.12.3.1

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
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
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:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).

Official description

Haystack is an end-to-end LLM framework that allows you to build applications powered by LLMs, Transformer models, vector search and more. Haystack clients that let their users create and run Pipelines from scratch are vulnerable to remote code executions. Certain Components in Haystack use Jinja2 templates, if anyone can create and render that template on the client machine they run any code. The vulnerability has been fixed with Haystack `2.3.1`.

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

The underlying weakness: Improper Neutralization of Special Elements Used in a Template Engine

The product uses a template engine to insert or process externally-influenced input, but it does not neutralize or incorrectly neutralizes special elements or syntax that can be interpreted as template expressions or other code directives when processed by the engine.

How developers prevent this class of flaw

  • Choose a template engine that offers a sandbox or restricted mode, or at least limits the power of any available expressions, function calls, or commands.
  • Use the template engine's sandbox or restricted mode, if available.

More Improper Neutralization of Special Elements Used in a Template Engine vulnerabilities (CWE-1336)

Timeline

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

References

Recent Improper Neutralization of Special Elements Used in a Template Engine vulnerabilities

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