Security readout for executives and security teams
Plain-English summary
This flaw can let an unauthenticated attacker bypass login and take over a frontend user account on affected October CMS sites. The key limiting factor is that the attacker must already know the Laravel secret key used for cookie encryption and signing.
Executive priority
Prioritize remediation for internet-facing October CMS sites with frontend user accounts. The required secret key lowers likelihood, but account takeover impact is high if that prerequisite is met.
Technical view
Affected october/system versions allow authentication bypass through a specially crafted unauthenticated request when the attacker possesses the Laravel secret key. The issue affects frontend users only. The vendor patched it in October CMS Build 472 and v1.1.5.
Likely exposure
Exposure is limited to October CMS deployments running october/system >=1.0.471 and <1.0.472, or >=1.1.1 and <1.1.5, with frontend user functionality enabled.
Exploitation context
The supplied sources do not report active exploitation, and this CVE is not marked KEV. Exploitation is network-accessible and unauthenticated, but high complexity because the Laravel secret key is required.
Researcher notes
Do not assume backend takeover from the provided evidence; the advisory scopes impact to frontend users. Validation should focus on version ranges, frontend account exposure, and whether the Laravel secret key may have been disclosed.
Mitigation direction
- Upgrade October CMS to Build 472, v1.1.5, or later vendor-supported versions.
- Confirm the october/system package is outside the affected version ranges.
- Review vendor advisory and linked commits before applying compensating controls.
- Protect and rotate exposed Laravel secret keys according to vendor guidance.
Validation and detection
- Inventory October CMS instances and identify the october/system package version.
- Check whether frontend user accounts are enabled on affected deployments.
- Verify deployed builds are Build 472, v1.1.5, or later.
- Review configuration handling for possible Laravel secret key exposure.
- Look for unexplained frontend account access around the disclosure window.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-287: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-29487 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
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:H/PR:N/UI:N/S:U/C:H/I:H/A:N2.25.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/octobercms/library/commit/016a297b1bec55d2e53bc889458ed2cb5c3e9374CVE reference · x_refsource_MISC
- https://github.com/octobercms/library/commit/5bd1a28140b825baebe6becd4f7562299d3de3b9CVE reference · x_refsource_MISC
- https://github.com/octobercms/october/security/advisories/GHSA-h76r-vgf3-j6w5CVE reference · x_refsource_CONFIRM
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 Authentication
Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.