How severe is CVE-2021-20153?

CVE-2021-20153 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20153 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20153?

CVE-2021-20153 affects Trendnet Tew-827dru Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20153?

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

When was CVE-2021-20153 published?

CVE-2021-20153 was published on 2021-12-30 and last updated on 2026-06-17.

CVE-2021-20153

CVE-2021-20153 is a medium-severity vulnerability in Trendnet Tew-827dru Firmware with a CVSS 3.x base score of 6.8. 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-59.

Key facts

Severity: Medium (CVSS 3.x base score 6.8)
CVSS v2: 6.9
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-59
Affected product: Trendnet Tew-827dru Firmware
Published: 2021-12-30
Last modified: 2026-06-17

Description

Trendnet AC2600 TEW-827DRU version 2.08B01 contains a symlink vulnerability in the bittorrent functionality. If enabled, the bittorrent functionality is vulnerable to a symlink attack that could lead to remote code execution on the device. If an end user inserts a flash drive with a malicious symlink on it that the bittorrent client can write downloads to, then a user is able to download arbitrary files to any desired location on the devices filesystem, which could lead to remote code execution. Example directories vulnerable to this include "config", "downloads", and "torrents", though it should be noted that "downloads" is the only vector that allows for arbitrary files to be downloaded to arbitrary locations.

Frequently asked questions

What is CVE-2021-20153?: Trendnet AC2600 TEW-827DRU version 2.08B01 contains a symlink vulnerability in the bittorrent functionality. If enabled, the bittorrent functionality is vulnerable to a symlink attack that could lead to remote code execution on the device. If an end user inserts a flash drive with a malicious symlink on it that the bittorrent client can write downloads to, then a user is able to download arbitrary files to any desired location on the devices filesystem, which could lead to remote code execution. Example directories vulnerable to this include "config", "downloads", and "torrents", though it should be noted that "downloads" is the only vector that allows for arbitrary files to be downloaded to arbitrary locations.
How severe is CVE-2021-20153?: CVE-2021-20153 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20153 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20153?: CVE-2021-20153 affects Trendnet Tew-827dru Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20153?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20153 published?: CVE-2021-20153 was published on 2021-12-30 and last updated on 2026-06-17.

References

https://www.tenable.com/security/research/tra-2021-54

Affected products (1)

cpe:2.3:o:trendnet:tew-827dru_firmware:2.08b01:*:*:*:*:*:*:*

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