CyberSecBulletin
CVE-2024-8763NVD status: Modified

lunary-ai/lunary: Inefficient Regular Expression Complexity

CVE-2024-8763 is a high-severity inefficient regular expression complexity vulnerability in lunary-ai/lunary from Lunary-ai, with a CVSS 3.0 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 1.4.23 as the first without the flaw, so updating lunary-ai/lunary to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.82% chance of exploitation within 30 days, higher than 58% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update lunary-ai/lunary to 1.4.23 or a later version.
  2. Update Lunary to 1.4.23 or a later version.
  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
Lunary-ailunary-ai/lunarybefore 1.4.231.4.23
LunaryLunarybefore 1.4.231.4.23

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
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (huntr.dev).

Official description

A Regular Expression Denial of Service (ReDoS) vulnerability exists in the lunary-ai/lunary repository, specifically in the compileTextTemplate function. The affected version is git be54057. An attacker can exploit this vulnerability by manipulating the regular expression /{{(.*?)}}/g, causing the server to hang indefinitely and become unresponsive to any requests. This is due to the regular expression's susceptibility to second-degree polynomial time complexity, which can be triggered by a large number of braces in the input.

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

The underlying weakness: Inefficient Regular Expression Complexity

The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

How developers prevent this class of flaw

  • Use regular expressions that do not support backtracking, e.g. by removing nested quantifiers.
  • Set backtracking limits in the configuration of the regular expression implementation, such as PHP's pcre.backtrack_limit. Also consider limits on execution time for the process.
  • Do not use regular expressions with untrusted input. If regular expressions must be used, avoid using backtracking in the expression.

More Inefficient Regular Expression Complexity vulnerabilities (CWE-1333)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Other vulnerabilities in lunary-ai/lunary

All lunary-ai/lunary vulnerabilities

Recent Inefficient Regular Expression Complexity vulnerabilities

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