PT-2021-5503 · D Link · D-Link Dir-809

Lnkvct + 2 · Published 2021-01-12 · Updated 2021-12-03 · CVE-2021-33266

Positive Technologies (AI Summary)

CVSS v3.1

10

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions D-Link DIR-809 devices with firmware through DIR-809Ax FW1.12WWB03 20190410

Description A stack buffer overflow issue exists in the FUN 8004776c function, located in the /formVirtualApp endpoint. This issue can be triggered via a crafted POST request, potentially allowing a remote attacker to execute arbitrary code in the system.

Recommendations For D-Link DIR-809 devices with firmware through DIR-809Ax FW1.12WWB03 20190410, as a temporary workaround, consider disabling the FUN 8004776c function in the /formVirtualApp endpoint until a patch is available. Restrict access to the /formVirtualApp endpoint to minimize the risk of exploitation. Avoid using crafted POST requests to the /formVirtualApp endpoint until the issue is resolved. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

BDU:2021-06353

CVE-2021-33266

Affected Products

D-Link Dir-809

References · 6

• 🔥 https://github.com/Lnkvct/IoT-poc/tree/master/D-Link-DIR809/vuln04 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2021-33266 · Security Note
• https://dlink.com/en/security-bulletin · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-33266 · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-06353 · Security Note
• https://t.me/cibsecurity/33239 · Telegram Post