What’s Vulnerable › Vulnerabilities

CVE-2021-28838

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-08-10 · updated 2026-06-17
• Weakness: CWE-476

Description

Null pointer dereference vulnerability in D-Link DAP-2310 2,10RC039, DAP-2330 1.10RC036 BETA, DAP-2360 2.10RC055, DAP-2553 3.10rc039 BETA, DAP-2660 1.15rc131b, DAP-2690 3.20RC115 BETA, DAP-2695 1.20RC093, DAP-3320 1.05RC027 BETA and DAP-3662 1.05rc069 in the sbin/httpd binary. The crash happens at the `atoi' operation when a specific network package are sent to the httpd binary.

Affected products

• Dlink Dap-2310 Firmware: through 2.10rc039
• Dlink Dap-2330 Firmware: before 1.10rc036; 1.10rc036-beta — fixed in 1.10rc036
• Dlink Dap-2360 Firmware: through 2.10rc055
• Dlink Dap-2553 Firmware: before 3.10rc039; 3.10rc039-beta — fixed in 3.10rc039
• Dlink Dap-2660 Firmware: through 1.15rc131b
• Dlink Dap-2690 Firmware: before 3.20rc115; 3.20rc115-beta — fixed in 3.20rc115
• D-Link DAP-2695: through 1.20rc093
• Dlink Dap-3320 Firmware: before 1.05rc027; 1.05rc027-beta — fixed in 1.05rc027
• Dlink Dap-3662 Firmware: before 1.05rc069; 1.05rc069-beta — fixed in 1.05rc069

How to fix

Upgrade to a fixed version: Dlink Dap-2330 Firmware 1.10rc036; Dlink Dap-2553 Firmware 3.10rc039; Dlink Dap-2690 Firmware 3.20rc115; Dlink Dap-3320 Firmware 1.05rc027; Dlink Dap-3662 Firmware 1.05rc069. Check the vendor advisory for mitigations.

References

• https://github.com/zyw-200/EQUAFL/blob/main/dlink-email-cve.pdf
• https://github.com/zyw-200/EQUAFL/blob/main/dlink-email-cve2.pdf
• https://www.dlink.com/en/security-bulletin/
• https://github.com/zyw-200/EQUAFL/blob/main/dlink-email-cve.pdf
• https://github.com/zyw-200/EQUAFL/blob/main/dlink-email-cve2.pdf
• https://www.dlink.com/en/security-bulletin/

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