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Vulnerability record · CVE-2021-37915 · published 28 October 2021

CVE-2021-37915: Grandstream ht801 firmware vulnerability

Grandstream · Ht801 Firmware

An issue was discovered on the Grandstream HT801 Analog Telephone Adaptor before 1.0.29.8. From the limited configuration shell, it is possible to set the malicious gdb_debug_server variable. As a result, after a reboot, the device downloads and executes malicious scripts from an attacker-defined host.

8.8 CVSS 3.1 High EPSS 2.0% · top 19.8%
8.8CVSS 3.1 base score, v2 9.0
2.0%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

An issue was discovered on the Grandstream HT801 Analog Telephone Adaptor before 1.0.29.8. From the limited configuration shell, it is possible to set the malicious gdb_debug_server variable. As a result, after a reboot, the device downloads and executes malicious scripts from an attacker-defined host.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://firmware.grandstream.com/BETA/Release_Note_HT80x_1.0.29.8.pdf Broken Link
http://www.grandstream.com/products/gateways-and-atas/analog-telephone-adaptors/product/ht801 ProductVendor Advisory
https://www.secforce.com/blog/exploiting-grandstream-ht801-ata-cve-2021-37748-cve-2021-37915/ ExploitThird Party Advisory
http://firmware.grandstream.com/BETA/Release_Note_HT80x_1.0.29.8.pdf Broken Link
http://www.grandstream.com/products/gateways-and-atas/analog-telephone-adaptors/product/ht801 ProductVendor Advisory
https://www.secforce.com/blog/exploiting-grandstream-ht801-ata-cve-2021-37748-cve-2021-37915/ ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.8CVE-2021-37748Grandstream ht801 firmware out-of-bounds write vulnerabilityMultiple buffer overflows in the limited configuration shell (/sbin/gs_config) on Grandstream HT801 devices before 1.0.29 allow remote authenticated …EPSS 7.4%8.8CVE-2020-5763Grandstream ht801 firmware inadequate encryption strength vulnerabilityGrandstream HT800 series firmware version 1.0.17.5 and below contain a backdoor in the SSH service. An authenticated remote attacker can obtain a roo…EPSS 2.7%7.8CVE-2020-5760Grandstream ht801 firmware os command injection vulnerabilityGrandstream HT800 series firmware version 1.0.17.5 and below is vulnerable to an OS command injection vulnerability. Unauthenticated remote attackers…EPSS 5.5%7.5CVE-2020-5761Grandstream ht801 firmware vulnerabilityGrandstream HT800 series firmware version 1.0.17.5 and below is vulnerable to CPU exhaustion due to an infinite loop in the TR-069 service. Unauthent…EPSS 4.1%7.5CVE-2020-5762Grandstream ht801 firmware null pointer dereference vulnerabilityGrandstream HT800 series firmware version 1.0.17.5 and below is vulnerable to a denial of service attack against the TR-069 service. An unauthenticat…EPSS 3.4%

Source: NIST National Vulnerability Database (record CVE-2021-37915), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.