How severe is CVE-2021-21740?

CVE-2021-21740 has a CVSS 3.x base score of 2.4, rated low severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-21740 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21740?

CVE-2021-21740 affects Zte Zxhn H2640 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21740?

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

When was CVE-2021-21740 published?

CVE-2021-21740 was published on 2021-08-09 and last updated on 2026-06-17.

CVE-2021-21740

CVE-2021-21740 is a low-severity vulnerability in Zte Zxhn H2640 Firmware with a CVSS 3.x base score of 2.4. 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: Low (CVSS 3.x base score 2.4)
CVSS v2: 2.1
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-59
Affected product: Zte Zxhn H2640 Firmware
Published: 2021-08-09
Last modified: 2026-06-17

Description

There is an information leak vulnerability in the digital media player (DMS) of ZTE's residential gateway product. The attacker could insert the USB disk with the symbolic link into the residential gateway, and access unauthorized directory information through the symbolic link, causing information leak.

Frequently asked questions

What is CVE-2021-21740?: There is an information leak vulnerability in the digital media player (DMS) of ZTE's residential gateway product. The attacker could insert the USB disk with the symbolic link into the residential gateway, and access unauthorized directory information through the symbolic link, causing information leak.
How severe is CVE-2021-21740?: CVE-2021-21740 has a CVSS 3.x base score of 2.4, rated low severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-21740 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21740?: CVE-2021-21740 affects Zte Zxhn H2640 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21740?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-21740 published?: CVE-2021-21740 was published on 2021-08-09 and last updated on 2026-06-17.

References

https://support.zte.com.cn/support/news/LoopholeInfoDetail.aspx?newsId=1017244

Affected products (1)

cpe:2.3:o:zte:zxhn_h2640_firmware:10.0.0c6_ty:*:*:*:*:*:*:*

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