← Vulnerability feed

Vulnerability record · CVE-2021-37748 · published 28 October 2021

CVE-2021-37748: Grandstream ht801 firmware out-of-bounds write vulnerability

Grandstream · Ht801 Firmware

Multiple buffer overflows in the limited configuration shell (/sbin/gs_config) on Grandstream HT801 devices before 1.0.29 allow remote authenticated users to execute arbitrary code as root via a crafted manage_if setting, thus bypassing the intended restrictions of this shell and taking full control of the device. There are default weak credentials that can be used to authenticate.

8.8 CVSS 3.1 High EPSS 7.4% · top 5.8% CWE-787 · Out-of-bounds write
8.8CVSS 3.1 base score, v2 9.0
7.4%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

Multiple buffer overflows in the limited configuration shell (/sbin/gs_config) on Grandstream HT801 devices before 1.0.29 allow remote authenticated users to execute arbitrary code as root via a crafted manage_if setting, thus bypassing the intended restrictions of this shell and taking full control of the device. There are default weak credentials that can be used to authenticate.

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://www.grandstream.com/products/gateways-and-atas/analog-telephone-adaptors/product/ht801 ProductVendor Advisory
https://github.com/SECFORCE/CVE-2021-37748 Third Party Advisory
https://www.secforce.com/blog/exploiting-grandstream-ht801-ata-cve-2021-37748-cve-2021-37915/ ExploitThird Party Advisory
http://www.grandstream.com/products/gateways-and-atas/analog-telephone-adaptors/product/ht801 ProductVendor Advisory
https://github.com/SECFORCE/CVE-2021-37748 Third Party Advisory
https://www.secforce.com/blog/exploiting-grandstream-ht801-ata-cve-2021-37748-cve-2021-37915/ ExploitThird Party Advisory

Track CVE-2021-37748 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

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

8.8CVE-2021-37915Grandstream ht801 firmware vulnerabilityAn issue was discovered on the Grandstream HT801 Analog Telephone Adaptor before 1.0.29.8. From the limited configuration shell, it is possible to se…EPSS 2.0%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%8.8CVE-2026-53266Linux kernel ebtables SNAT out-of-bounds write in ARP rewriteThe ebtables SNAT target rewrites the ARP sender hardware address via skb_store_bits() without first making that range writable. When the ARP SHA byt…KEVEPSS 0.65%analysed8.8CVE-2026-87491Google Chrome V8 out-of-bounds write enables sandbox code executionChrome before 153.0.8010.36 contains an out-of-bounds write in the V8 JavaScript engine. A crafted HTML page can trigger the memory corruption, and b…KEVEPSS 3.1%analysed9.8CVE-2025-25249Fortinet FortiOS and FortiSwitchManager heap buffer overflow via crafted packetsA heap-based buffer overflow (CWE-122/CWE-787) in Fortinet FortiOS 6.4 through 7.6.3 and FortiSwitchManager 7.0 through 7.2.6 lets an unauthenticated…KEVEPSS 3.9%analysed

Source: NIST National Vulnerability Database (record CVE-2021-37748), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.