CVE-2020-5763

Exp

Grandstream HT800 series firmware version 1.0.17.5 and below contain a backdoor in the SSH service. An authenticated remote attacker can obtain a root shell by correctly answering a challenge prompt.

Published: 2020-07-29 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-5763 is rated High Exploit Risk (79.5/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.62%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-5763

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-5763

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-15 0.94% 1.62% +0.68%
2 2026-03-23 1.31% 0.94% -0.37%
3 2025-11-21 1.31%

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-5763

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
9.0 2.0 HIGH
AV:N/AC:L/Au:S/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
8.0 10.0 [email protected]

Weakness enumeration for CVE-2020-5763

Affected software / configurations for CVE-2020-5763

Vendor Product Version Raw CPE
grandstream ht801_firmware <= 1.0.17.5 cpe:2.3:o:grandstream:ht801_firmware:*:*:*:*:*:*:*:*
grandstream ht802_firmware <= 1.0.17.5 cpe:2.3:o:grandstream:ht802_firmware:*:*:*:*:*:*:*:*
grandstream ht812_firmware <= 1.0.17.5 cpe:2.3:o:grandstream:ht812_firmware:*:*:*:*:*:*:*:*
grandstream ht814_firmware <= 1.0.17.5 cpe:2.3:o:grandstream:ht814_firmware:*:*:*:*:*:*:*:*
grandstream ht818_firmware <= 1.0.17.5 cpe:2.3:o:grandstream:ht818_firmware:*:*:*:*:*:*:*:*
grandstream ht813_firmware <= 1.0.17.5 cpe:2.3:o:grandstream:ht813_firmware:*:*:*:*:*:*:*:*

References for CVE-2020-5763

URL Tags
https://www.tenable.com/security/research/tra-2020-43 Exploit Third Party Advisory
https://www.tenable.com/security/research/tra-2020-47 Third Party Advisory VDB Entry
cvelogic Threat Intelligence