CyberSecBulletin
CVE-2025-15099NVD status: Analyzed

sim: Improper Authentication

CVE-2025-15099 is a critical-severity improper authentication vulnerability in sim from SimStudioAI, 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 sim versions: 0.5.0; 0.5.1; 0.5.2, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of sim you run against the affected versions below, and install the vendor's latest release.
  2. 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
Simstudioaisim0.5.0; 0.5.1; 0.5.2; 0.5.3; 0.5.4; 0.5.5; 0.5.6; 0.5.7; and 20 more rangesNot stated

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 NVD.

Scoring systemScoreSeverityScored by
CVSS 4.05.5MediumCNA (vuldb.com)
CVSS 3.17.3HighCNA (vuldb.com)
CVSS 3.19.8CriticalNVD
CVSS 2.07.5HighCNA (vuldb.com)

Official description

A vulnerability was identified in simstudioai sim up to 0.5.27. This vulnerability affects unknown code of the file apps/sim/lib/auth/internal.ts of the component CRON Secret Handler. The manipulation of the argument INTERNAL_API_SECRET leads to improper authentication. It is possible to initiate the attack remotely. The exploit is publicly available and might be used. The identifier of the patch is e359dc2946b12ed5e45a0ec9c95ecf91bd18502a. Applying a patch is the recommended action to fix this issue.

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

The underlying weakness: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How developers prevent this class of flaw

  • Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

More Improper Authentication vulnerabilities (CWE-287)

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

Third-party and government advisories

Technical write-ups (may include proof of concept)

Other references

Other vulnerabilities in sim

All sim vulnerabilities

Recent Improper Authentication vulnerabilities

Spotted an error? Tell us.