Security readout for executives and security teams
Plain-English summary
Cachet status page servers before 2.5.1 let any authenticated user abuse configuration editing to reach server-side code execution. This matters because even low-privileged dashboard accounts could potentially take over the application server.
Executive priority
Prioritize remediation for any internet-reachable or shared-user Cachet deployment. The business risk is full compromise of a public status page server, with possible data exposure, service disruption, and reputational impact.
Technical view
The issue is newline injection in Cachet configuration values, including mail settings. Sources state authenticated User or Admin accounts could exploit configuration editing before 2.5.1. Version 2.5.1 changed UpdateConfigCommandHandler to block newline characters in new configuration values.
Likely exposure
Exposure is likely where Cachet before 2.5.1 is deployed and its administration dashboard is reachable by untrusted or weakly controlled authenticated users.
Exploitation context
The CVE is not listed as KEV in the supplied bundle, and no source here confirms active exploitation. Public analysis explains the bug class and impact, so treat exposed instances as high priority.
Researcher notes
Evidence is strongest for Cachet prior to 2.5.1 and authenticated dashboard access. Do not assume other products are affected. Validation should focus on version, dashboard reachability, account control, and historical configuration activity.
Mitigation direction
- Upgrade Cachet to version 2.5.1 or later.
- Restrict administration dashboard access to trusted source IP addresses.
- Review and remove dashboard accounts that should not edit configuration.
- Monitor configuration changes and investigate unexpected mail-setting edits.
Validation and detection
- Inventory Cachet deployments and confirm each version is at least 2.5.1.
- Verify the administration dashboard is not reachable from untrusted networks.
- Review authenticated user accounts with dashboard access.
- Check application logs for unexpected configuration edits before remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-93: Exact CWE lookup
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Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-39172 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/fiveai/Cachet/security/advisories/GHSA-9jxw-cfrh-jxq6CVE reference · x_refsource_CONFIRM
- https://github.com/fiveai/Cachet/releases/tag/v2.5.1CVE reference · x_refsource_MISC
- https://blog.sonarsource.com/cachet-code-execution-via-laravel-configuration-injection/CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of CRLF Sequences ('CRLF Injection')
Improper Neutralization of CRLF Sequences ('CRLF Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.