Tenable Nessus 8.9.0 < 8.13.2 Multiple Vulnerabilities (TNS-2021-05)

high Nessus Plugin ID 148297
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Synopsis

Tenable Nessus running on the remote host is affected by multiple vulnerabilities.

Description

According to its self-reported version, the Tenable Nessus application running on the remote host is 8.9.0 prior to 8.13.2. It is, therefore, affected by multiple vulnerabilities:

- An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled. (CVE-2021-3449)

- The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded elliptic curve parameters was added as an additional strict check. An error in the implementation of this check meant that the result of a previous check to confirm that certificates in the chain are valid CA certificates was overwritten. This effectively bypasses the check that non-CA certificates must not be able to issue other certificates. If a 'purpose' has been configured then there is a subsequent opportunity for checks that the certificate is a valid CA. All of the named 'purpose' values implemented in libcrypto perform this check. Therefore, where a purpose is set the certificate chain will still be rejected even when the strict flag has been used. A purpose is set by default in libssl client and server certificate verification routines, but it can be overridden or removed by an application. In order to be affected, an application must explicitly set the X509_V_FLAG_X509_STRICT verification flag and either not set a purpose for the certificate verification or, in the case of TLS client or server applications, override the default purpose. (CVE-2021-3450)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Tenable Nessus version 8.13.2 or later.

See Also

http://www.nessus.org/u?4ceab20f

https://www.tenable.com/security/tns-2021-05

https://www.openssl.org/news/vulnerabilities.html#CVE-2021-3449

https://www.openssl.org/news/vulnerabilities.html#CVE-2021-3450

Plugin Details

Severity: High

ID: 148297

File Name: nessus_tns_2021_04.nasl

Version: 1.4

Type: remote

Family: Misc.

Published: 4/2/2021

Updated: 4/5/2021

Dependencies: nessus_detect.nasl

Risk Information

CVSS Score Source: CVE-2021-3450

VPR

Risk Factor: High

Score: 8.3

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.3

Vector: AV:N/AC:M/Au:N/C:P/I:P/A:N

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7.4

Temporal Score: 6.4

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:tenable:nessus

Required KB Items: installed_sw/nessus

Exploit Ease: No known exploits are available

Patch Publication Date: 4/1/2021

Vulnerability Publication Date: 4/1/2021

Reference Information

CVE: CVE-2021-3449, CVE-2021-3450

IAVA: 2021-A-0149