How severe is CVE-2021-27342?

CVE-2021-27342 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-27342 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27342?

CVE-2021-27342 affects Dlink Dir-842e Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27342?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-27342 published?

CVE-2021-27342 was published on 2021-05-17 and last updated on 2026-06-17.

CVE-2021-27342

CVE-2021-27342 is a medium-severity vulnerability in Dlink Dir-842e Firmware with a CVSS 3.x base score of 5.9. 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-203.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 4.3
EPSS exploit prediction: 5% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-203
Affected product: Dlink Dir-842e Firmware
Published: 2021-05-17
Last modified: 2026-06-17

Description

An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR-842 firmware version 3.0.2 allows a remote attacker to circumvent the anti-brute-force cool-down delay period via a timing-based side-channel attack

Frequently asked questions

What is CVE-2021-27342?: An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR-842 firmware version 3.0.2 allows a remote attacker to circumvent the anti-brute-force cool-down delay period via a timing-based side-channel attack
How severe is CVE-2021-27342?: CVE-2021-27342 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-27342 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27342?: CVE-2021-27342 affects Dlink Dir-842e Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27342?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-27342 published?: CVE-2021-27342 was published on 2021-05-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:dlink:dir-842e_firmware:*:*:*:*:*:*:*:*

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