Multiple vulnerabilities in Tenable Nessus

Published: 2021-06-30 | Updated: 2022-01-17

Risk	Medium
Patch available	YES
Number of vulnerabilities	5
CVE-ID	CVE-2018-20843 CVE-2019-15903 CVE-2019-16168 CVE-2021-20099 CVE-2021-20100
CWE-ID	CWE-611 CWE-125 CWE-369 CWE-264
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available. Public exploit code for vulnerability #2 is available. Public exploit code for vulnerability #3 is available.
Vulnerable software	Tenable Nessus Client/Desktop applications / Software for system administration
Vendor	Tenable Network Security

Security Bulletin

This security bulletin contains information about 5 vulnerabilities.

1) XML External Entity injection

EUVDB-ID: #VU18923

Risk: Medium

CVSSv4.0: 7.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2018-20843

CWE-ID: CWE-611 - Improper Restriction of XML External Entity Reference ('XXE')

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to insufficient validation of user-supplied XML input including XML names that contain a large number of colons. A remote attacker can pass a specially crafted XML code to the affected application and view contents of arbitrary files on the system or initiate requests to external systems.

Successful exploitation of the vulnerability may allow an attacker to view contents of arbitrary file on the server or perform network scanning of internal and external infrastructure.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Tenable Nessus: 8.0.0 - 8.14.0

CPE2.3

External links

https://www.tenable.com/security/tns-2021-11

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

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.

2) Out-of-bounds read

EUVDB-ID: #VU21091

Risk: Medium

CVSSv4.0: 2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2019-15903

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information or perform denial of service (DoS) attack.

The vulnerability exists due to a boundary error when processing XML documents within the expat library. A remote attacker can create a specially crafted XML file, pass it to the affected application, trigger out-of-bounds read error and read contents of memory on the system or crash the affected application.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Tenable Nessus: 8.0.0 - 8.14.0

CPE2.3

External links

https://www.tenable.com/security/tns-2021-11

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

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) Division by zero

EUVDB-ID: #VU23188

Risk: Low

CVSSv4.0: 2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2019-16168

CWE-ID: CWE-369 - Divide By Zero

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to perform a denial of service attack.

The vulnerability exists due to a division by zero error within the whereLoopAddBtreeIndex in sqlite3.c due to improper input validation in the sqlite_stat1 sz field. A remote attacker can pass specially crafted data to the application, trigger division by zero error and crash the vulnerable application.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Tenable Nessus: 8.0.0 - 8.14.0

CPE2.3

External links

https://www.tenable.com/security/tns-2021-11

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

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.

4) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU54452

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-20099

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions, which leads to security restrictions bypass and privilege escalation.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Tenable Nessus: 8.0.0 - 8.14.0

CPE2.3

External links

https://www.tenable.com/security/tns-2021-11

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU54453

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-20100

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions, which leads to security restrictions bypass and privilege escalation.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Tenable Nessus: 8.0.0 - 8.14.0

CPE2.3

External links

https://www.tenable.com/security/tns-2021-11

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.