An authenticated attacker could utilize the identical agent and cluster node linking keys to potentially allow for a scenario where unauthorized disclosure of agent logs and data is present.

An authenticated attacker could read Nessus Debug Log file attachments from the web UI without having the correct privileges to do so. This may lead to the disclosure of information on the scan target and/or the Nessus scan to unauthorized parties able to reach the Nessus instance.

Insufficiently Protected Credentials: An authenticated user with debug privileges can retrieve stored Nessus policy credentials from the “nessusd” process in cleartext via process dumping. The affected products are all versions of Nessus Essentials and Professional. The vulnerability allows an attacker to access credentials stored in Nessus scanners, potentially compromising its customers’ network of assets.

An authenticated attacker could read arbitrary files from the underlying operating system of the scanner using a custom crafted compliance audit file without providing any valid SSH credentials.

An authenticated attacker could create an audit file that bypasses PowerShell cmdlet checks and executes commands with administrator privileges.

The BN_mod_sqrt() function, which computes a modular square root, contains a bug that can cause it to loop forever for non-prime moduli. Internally this function is used when parsing certificates that contain elliptic curve public keys in compressed form or explicit elliptic curve parameters with a base point encoded in compressed form. It is possible to trigger the infinite loop by crafting a certificate that has invalid explicit curve parameters. Since certificate parsing happens prior to verification of the certificate signature, any process that parses an externally supplied certificate may thus be subject to a denial of service attack. The infinite loop can also be reached when parsing crafted private keys as they can contain explicit elliptic curve parameters. Thus vulnerable situations include: - TLS clients consuming server certificates - TLS servers consuming client certificates - Hosting providers taking certificates or private keys from customers - Certificate authorities parsing certification requests from subscribers - Anything else which parses ASN.1 elliptic curve parameters Also any other applications that use the BN_mod_sqrt() where the attacker can control the parameter values are vulnerable to this DoS issue. In the OpenSSL 1.0.2 version the public key is not parsed during initial parsing of the certificate which makes it slightly harder to trigger the infinite loop. However any operation which requires the public key from the certificate will trigger the infinite loop. In particular the attacker can use a self-signed certificate to trigger the loop during verification of the certificate signature. This issue affects OpenSSL versions 1.0.2, 1.1.1 and 3.0. It was addressed in the releases of 1.1.1n and 3.0.2 on the 15th March 2022. Fixed in OpenSSL 3.0.2 (Affected 3.0.0,3.0.1). Fixed in OpenSSL 1.1.1n (Affected 1.1.1-1.1.1m). Fixed in OpenSSL 1.0.2zd (Affected 1.0.2-1.0.2zc).

Expat (aka libexpat) before 2.4.4 has an integer overflow in the doProlog function.

Expat (aka libexpat) before 2.4.4 has a signed integer overflow in XML_GetBuffer, for configurations with a nonzero XML_CONTEXT_BYTES.

storeAtts in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

nextScaffoldPart in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

lookup in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

defineAttribute in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

build_model in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

addBinding in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.

In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).

Nessus versions 8.15.2 and earlier were found to contain a local privilege escalation vulnerability which could allow an authenticated, local administrator to run specific executables on the Nessus Agent host. Tenable has included a fix for this issue in Nessus 10.0.0. The installation files can be obtained from the Tenable Downloads Portal (https://www.tenable.com/downloads/nessus).

Nessus Agent versions 8.2.5 and earlier were found to contain a privilege escalation vulnerability which could allow a Nessus administrator user to upload a specially crafted file that could lead to gaining administrator privileges on the Nessus host.

Nessus versions 8.13.2 and earlier were found to contain a privilege escalation vulnerability which could allow a Nessus administrator user to upload a specially crafted file that could lead to gaining administrator privileges on the Nessus host.

Nessus Agent 8.2.4 and earlier for Windows were found to contain multiple local privilege escalation vulnerabilities which could allow an authenticated, local administrator to run specific Windows executables as the Nessus host. This is different than CVE-2021-20099.