How severe is CVE-2021-42887?

CVE-2021-42887 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-2021-42887 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 43% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42887?

CVE-2021-42887 affects Totolink Ex1200t Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42887?

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-2021-42887 published?

CVE-2021-42887 was published on 2022-06-03 and last updated on 2026-06-17.

CVE-2021-42887

CVE-2021-42887 is a critical-severity vulnerability in Totolink Ex1200t Firmware with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 43% places it in the 99th percentile, indicating an elevated likelihood of exploitation.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 43% (99th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Totolink Ex1200t Firmware
Published: 2022-06-03
Last modified: 2026-06-17

Description

In TOTOLINK EX1200T V4.1.2cu.5215, an attacker can bypass login by sending a specific request through formLoginAuth.htm.

Frequently asked questions

What is CVE-2021-42887?: In TOTOLINK EX1200T V4.1.2cu.5215, an attacker can bypass login by sending a specific request through formLoginAuth.htm.
How severe is CVE-2021-42887?: CVE-2021-42887 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-2021-42887 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 43% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42887?: CVE-2021-42887 affects Totolink Ex1200t Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42887?: 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-2021-42887 published?: CVE-2021-42887 was published on 2022-06-03 and last updated on 2026-06-17.

References

https://github.com/p1Kk/vuln/blob/main/totolink_ex1200t_login_bypass.md

Affected products (1)

cpe:2.3:o:totolink:ex1200t_firmware:4.1.2cu.5215:*:*:*:*:*:*:*

More vulnerabilities in Totolink Ex1200t Firmware

CVE-2025-51451 — Critical (CVSS 9.8): In TOTOLINK EX1200T firmware 4.1.2cu.5215, an attacker can bypass login by sending a specific request through…
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CVE-2025-28039 — Critical (CVSS 9.8): TOTOLINK EX1200T V4.1.2cu.5232_B20210713 was found to contain a pre-auth remote command execution vulnerability in the…
CVE-2025-28038 — Critical (CVSS 9.8): TOTOLINK EX1200T V4.1.2cu.5232_B20210713 was found to contain a pre-auth remote command execution vulnerability in the…
CVE-2023-52032 — Critical (CVSS 9.8): TOTOlink EX1200T V4.1.2cu.5232_B20210713 was discovered to contain a remote command execution (RCE) vulnerability via…
CVE-2021-42890 — Critical (CVSS 9.8): TOTOLINK EX1200T V4.1.2cu.5215 contains a remote command injection vulnerability in function NTPSyncWithHost of the…

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