CVE-2026-109445
PLANET GS-5220-8P2T2S Stack Buffer Overflow via webstax_auth Cookie
PLANET GS-5220-8P2T2S (hardware version 3.0) firmware versions before 3.2412b261008 contains a stack-based buffer overflow vulnerability that allows unauthenticated attackers to corrupt stack memory by submitting an oversized webstax_auth HTTP Cookie value that is copied into a fixed-size stack buffer without length validation. Attackers can send a crafted unauthenticated HTTP request with an oversized cookie to overwrite the saved return address and corrupt stack memory, leading to memory corruption and potential denial of service on the device.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| PLANET GS-5220-8P2T2S PLANET Technology Corp. |
≥ 0; < 3.2412b261008 (affected, custom)
Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 9.3 critical |
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 9.8 critical |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | CNA: VulnCheck |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://www.planet.com.tw/en/support/security-advisory/12CNA: VulnCheck · vendor-advisory, patch
- https://www.vulncheck.com/advisories/planet-gs-5220-8p2t2s-stack-buffer-overflow-via-webstax-auth-cookieCNA: VulnCheck · third-party-advisory
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