CVE-2021-34203 json
D-Link DIR-2640-US 1.01B04 is vulnerable to Incorrect Access Control.
published 2021-06-16 5 y ago modified 2026-07-09 4 mo ago also EUVD-2021-20865
- cvss
- 8.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 68%
- public exploits
- 0
- none known
Summary
D-Link DIR-2640-US 1.01B04 is vulnerable to Incorrect Access Control. Router ac2600 (dir-2640-us), when setting PPPoE, will start quagga process in the way of whole network monitoring, and this function uses the original default password and port. An attacker can easily use telnet to log in, modify routing information, monitor the traffic of all devices under the router, hijack DNS and phishing attacks. In addition, this interface is likely to be questioned by customers as a backdoor, because the interface should not be exposed.
Exploit prediction
1.20% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/liyansong2018/CVE/tree/main/2021/CVE-2021-34203 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| NVD | 2.0 | 4.8 | AV:A/AC:L/Au:N/C:P/I:P/A:N |
Classification
- Weakness
-
- CWE-1188 Initialization of a Resource with an Insecure Default
References
-
github.com
/liyansong2018/CVE/tree/main/2021/CVE-2021-34203
exploit, third-party-advisory
-
dlink.com
/en/security-bulletin/
vendor-advisory
Sources
- CVE List CVE-2021-34203
- NVD CVE-2021-34203
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