CVE intelligence and bounded remediation
CVE-2018-12103 — Dlink Dir-890L Firmware security vulnerability
An issue was discovered on D-Link DIR-890L with firmware 1.21B02beta01 and earlier, DIR-885L/R with firmware 1.21B03beta01 and earlier, and DIR-895L/R with firmware 1.21B04beta04 and earlier devices (all hardware revisions). Due to the predictability of the /docs/captcha_(number).jpeg URI, being local to the network, but unauthenticated to the administrator's panel, an attacker can disclose the CAPTCHAs used by the access point and can elect to load the CAPTCHA of their choosing, leading to unauthorized login attempts to the access point.
- Severity
- Medium
- CVSS
- 6.5 (3.0)
- Published
- 2018-07-05
- CISA KEV
- Not currently listed
- Ecosystem
- operating-system
- Weaknesses
- CWE-863
Affected products
- dlink / dir-890l_firmware
- d-link / dir-885l/r_firmware
- d-link / dir-895l/r_firmware
Matched remediation archetype
Authorization bypass, IDOR, and cross-tenant access
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
- Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
- Use synthetic fixtures to compare intended access matrices without accessing another user's real data.
Remediate safely
- Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
- Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
- Add deny-by-default policy tests for horizontal and vertical access across every affected transport.
Authoritative sources
Complete CVE record and remediation plan
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