CVE-2020-5759

published 2020-07-17

CVE-2020-5759: Grandstream UCM6200 series firmware version 1.0.20.23 and below is vulnerable to OS command injection via SSH. An authenticated remote attacker can execute…

Priority P2 66 critical 9.8 CVSS 3.1

AV N AC L PR N UI N S U C H I H A H

Grandstream UCM6200 series firmware version 1.0.20.23 and below is vulnerable to OS command injection via SSH. An authenticated remote attacker can execute commands as the root user by issuing a specially crafted "unset" command.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
grandstream	ucm6202_firmware	<= 1.0.20.23	—
grandstream	ucm6204_firmware	<= 1.0.20.23	—
grandstream	ucm6208_firmware	<= 1.0.20.23	—

Detection & IOCs extracted from sources · hover to see the quote

port 1270↗

command unset↗

• → Monitor SSH sessions to Grandstream UCM6200 series devices for use of the 'unset' keyword in the config shell, which is the attack vector for CVE-2020-5759. ↗
• → Alert on unexpected outbound connections or bind shells spawned from the UCM6200 process space, consistent with post-exploitation activity following SSH command injection. ↗
• → Scope detection to Grandstream UCM6200 series firmware version 1.0.20.23 and below, as these are the affected versions. ↗

• · Exploitation requires prior authentication; this is not an unauthenticated attack vector. Detection should focus on authenticated SSH sessions abusing the config shell. ↗

CVSS provenance

nvd v3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd v2.0 10.0 CRITICAL AV:N/AC:L/Au:N/C:C/I:C/A:C

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.

CWE-78