Remote code execution in Zyxel NetAtlas EMS (Apache Log4j component)
| Risk | Critical |
| Patch available | NO |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2021-44228 CVE-2021-45046 CVE-2021-4104 |
| CWE-ID | CWE-94 CWE-502 |
| Exploitation vector | Network |
| Public exploit |
Vulnerability #1 is being exploited in the wild. Vulnerability #2 is being exploited in the wild. |
| Vulnerable software Subscribe |
NetAtlas Element Management System (EMS) Server applications / Remote management servers, RDP, SSH |
| Vendor | ZyXEL Communications Corp. |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
1) Code Injection
EUVDB-ID: #VU58816
Risk: Critical
CVSSv3.1: 9.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:U/RC:C]
CVE-ID: CVE-2021-44228
CWE-ID:
CWE-94 - Improper Control of Generation of Code ('Code Injection')
Exploit availability: Yes
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to improper input validation when processing LDAP requests. A remote attacker can send a specially crafted request to the application and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Note, we are aware of attackers exploiting the vulnerability in the wild.
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.
Vulnerable software versionsNetAtlas Element Management System (EMS): All versions
External linkshttp://www.zyxel.com/support/Zyxel_security_advisory_for_Apache_Log4j_RCE_vulnerability.shtml
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
Yes. This vulnerability is being exploited in the wild.
2) Code Injection
EUVDB-ID: #VU58976
Risk: High
CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:U/RC:C]
CVE-ID: CVE-2021-45046
CWE-ID:
CWE-94 - Improper Control of Generation of Code ('Code Injection')
Exploit availability: Yes
DescriptionThe vulnerability allows a remote attacker to compromise the affected system.
The
vulnerability exists due to incomplete patch in Apache Log4j 2.15.0 for
a code injection vulnerability #VU58816 (CVE-2021-44228) in certain
non-default configurations. A remote attacker with control over Thread
Context Map (MDC) input data when the logging configuration uses a
non-default Pattern Layout with either a Context Lookup (for example,
$${ctx:loginId}) or a Thread Context Map pattern (%X, %mdc, or %MDC) can
pass malicious data using a JNDI Lookup pattern and perform a denial of
service (DoS) attack, exfiltrate data or execute arbitrary code.
Later discovery demonstrates a remote code execution on macOS but no other tested environments.
MitigationCybersecurity Help is currently unaware of any official solution to address this vulnerability.
Vulnerable software versionsNetAtlas Element Management System (EMS): All versions
External linkshttp://www.zyxel.com/support/Zyxel_security_advisory_for_Apache_Log4j_RCE_vulnerability.shtml
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
3) Deserialization of Untrusted Data
EUVDB-ID: #VU58977
Risk: Medium
CVSSv3.1: 7.4 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:U/RC:C]
CVE-ID: CVE-2021-4104
CWE-ID:
CWE-502 - Deserialization of Untrusted Data
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in JMSAppender, when the attacker has write access to the Log4j configuration. The attacker can provide TopicBindingName and TopicConnectionFactoryBindingName configurations causing JMSAppender to perform JNDI requests that result in remote code execution.
Note this issue only affects Log4j 1.2 when specifically configured to
use JMSAppender, which is not the default.
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.
Vulnerable software versionsNetAtlas Element Management System (EMS): All versions
External linkshttp://www.zyxel.com/support/Zyxel_security_advisory_for_Apache_Log4j_RCE_vulnerability.shtml
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
