How severe is CVE-2020-9277?

CVE-2020-9277 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-9277 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-9277?

CVE-2020-9277 affects Dlink Dsl-2640b Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-9277?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-9277 published?

CVE-2020-9277 was published on 2020-04-20 and last updated on 2026-06-17.

CVE-2020-9277

CVE-2020-9277 is a critical-severity vulnerability in Dlink Dsl-2640b Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Dlink Dsl-2640b Firmware
Published: 2020-04-20
Last modified: 2026-06-17

Description

An issue was discovered on D-Link DSL-2640B B2 EU_4.01B devices. Authentication can be bypassed when accessing cgi modules. This allows one to perform administrative tasks (e.g., modify the admin password) with no authentication.

Frequently asked questions

What is CVE-2020-9277?: An issue was discovered on D-Link DSL-2640B B2 EU_4.01B devices. Authentication can be bypassed when accessing cgi modules. This allows one to perform administrative tasks (e.g., modify the admin password) with no authentication.
How severe is CVE-2020-9277?: CVE-2020-9277 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-9277 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-9277?: CVE-2020-9277 affects Dlink Dsl-2640b Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-9277?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-9277 published?: CVE-2020-9277 was published on 2020-04-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:dlink:dsl-2640b_firmware:eu_4.01b:*:*:*:*:*:*:*

More vulnerabilities in Dlink Dsl-2640b Firmware

CVE-2020-9279 — Critical (CVSS 9.8): An issue was discovered on D-Link DSL-2640B B2 EU_4.01B devices. A hard-coded account allows management-interface login…
CVE-2020-9275 — Critical (CVSS 9.8): An issue was discovered on D-Link DSL-2640B B2 EU_4.01B devices. A cfm UDP service listening on port 65002 allows…
CVE-2020-9278 — Critical (CVSS 9.1): An issue was discovered on D-Link DSL-2640B B2 EU_4.01B devices. The device can be reset to its default configuration…
CVE-2020-9276 — High (CVSS 8.8): An issue was discovered on D-Link DSL-2640B B2 EU_4.01B devices. The function do_cgi(), which processes cgi requests…
CVE-2012-1308 — Medium (CVSS 6.8): Cross-site request forgery (CSRF) vulnerability in redpass.cgi in D-Link DSL-2640B Firmware EU_4.00 allows remote…

All CVEs affecting Dlink Dsl-2640b Firmware →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →