Category Archives: Potential Risk of CVE

weekly security focus – memory leak vulnerability in vmci module (cve-2020-3959)

Preface: TCP / IP design restrictions have introduced security vulnerabilities to transport protocols.

Security focus: Memory leak vulnerability in VMCI module (CVE-2020-3959) – VMware ESXi, Workstation and Fusion contain a memory leak vulnerability in the VMCI module. It lets local non-administrative user send a malformed packet to a virtual machine. Such action may be able to crash the virtual machine’s vmx process leading to a partial denial of service.

Possible root cause: Attacker send malform packets containing null value in protocol field. The Virtual Machine Communication Interface will let such a packet in as an unclassified one. Though nowadays the null value in the Protocol field is reserved for IPv6 Hop-by-Hop Option (HOPOPT), not every server can receive and correctly process such a packet. And if such packets come in large quantities, their analysis will consume a large percentage of system resources, or exhaust them entirely and cause a server failure.

Remark: According to the RFC rules, the IP packet header should contain information on its transport level protocol in the Protocol field.

Official details please find follow link: https://www.vmware.com/security/advisories/VMSA-2020-0011.html

NSA preemptive curb threats factor – an exploitation of exim design weakness – 29th May 2020

Preface: The severity depends on your configuration, said vendor. It depends on how close to the standard configuration your Exim runtime configuration is. Jun 2019

Headline news on 28th May 2020 – The National Security Agency (NSA) has released a cybersecurity advisory on Russian advanced persistent threat (APT) group Sandworm exploiting a vulnerability—CVE-2019-10149—in Exim Mail Transfer Agent (MTA) software. Exim is growing in popularity because it is open source. An unauthenticated remote attacker can use this vulnerability to send a specially crafted email to execute commands with root privileges, allowing the attacker to install programs, modify data, and create new accounts.

The design weakness origin: The vulnerability was patched in Exim 4.92, released on February 10, 2019. The vulnerable code is in “deliver_message()”. A vulnerability exists because the email address in the deliver_message() function in /src/deliver.c is not fully validated. So local attackers simply send emails to “${run{…}}@localhost”. Since “localhost” is a local domain of Exim) and execute as root (system privileges).

Action: Apply Exim Updates Immediately

NSA official announcement – https://media.defense.gov/2020/May/28/2002306626/-1/-1/0/CSA%20Sandworm%20Actors%20Exploiting%20Vulnerability%20in%20Exim%20Transfer%20Agent%2020200528.pdf

Critical Android bug 8,8.1 and 9 (CVE-2020-0096) – 27th May 2020

Preface: As of April 2020, 37.4% of Android devices run Pie, making it the most popular Android version.

Vulnerability details: A critical vulnerability on Android causes privilege-escalation The impact is that it allows attackers to hijack any app on an infected phone, it is much more difficult to detect, the name so called StrandHogg 2.0. For more details, please reference to follow link. https://promon.co/strandhogg-2-0/

Closer look to vulnerability: The bug so called a “StrandHogg 2.0” vulnerability (CVE-2020-0096) found by Promon researchers. This is because the vulnerability is similar to the original StrandHogg bug discovered last year. Like the original, a malicious app installed on a device can hide behind legitimate apps. When a normal app icon is clicked, a malicious overlay is instead executed, which can harvest login credentials for the legitimate app.

Official announcement – Android Security Bulletin May 2020: https://source.android.com/security/bulletin/2020-05-01

Under our investigation – One could potentially recover developer defined permissions by examining the permission checks in application code and the filters declared in the application manifest. Stay tuned!

Security focus – Bind vulnerability (CVE-2020-8616) – 20th May 2020

Preface: BIND is open source software that enables you to publish your Domain Name System (DNS) information on the Internet, and to resolve DNS queries for your users.

About traditional DNS attack: An example of a DoS attack is the SYN
flood, which uses a the TCP SYN packet to create half open TCP connections on the server, which lead to the server having a massive pool of half open TCP connections and not allowing for anymore connections from legitimate hosts.

Vulnerability details: The recursion refers to the process of having the DNS server itself to make queries to other DNS servers on behalf of the client who made the original request.
In order for a server performing recursion to locate records in the DNS graph it must be capable of processing referrals, such as those received when it attempts to query an authoritative server for a record which is delegated elsewhere. But the original design did not have limitation. So such circumstance can potentially degrade the performance of DNS server. Official announcement shown in this url: https://kb.isc.org/docs/cve-2020-8616

Additional vulnerability: https://kb.isc.org/docs/cve-2020-8617

VMware Cloud Director updates address Code Injection Vulnerability (CVE-2020-3956) – 22nd May 2020

Preface: Don’t underestimate the vulnerabilities discovered in the past, it will cause trouble for your cloud or system.

Background: VMware vCloud Director is a management tool for private and hybrid cloud architectures. Top Industries that use VMware vCloud Director are Financial Services, Insurance Program Managers Group, & business technology services provider.

Vulnerability details: VMware officially announced on May 19, 2020. Suppliers urge customers to immediately repair or apply workarounds. The details of the vulnerability pointed out by the vendor is a code injection vulnerability in VMware Cloud Director. The product failed to properly handle the input that led to the code injection vulnerability. For more details, please refer to following url: https://www.vmware.com/security/advisories/VMSA-2020-0010.html

Our observation: With reference to the workaround provided by vendor. The hints of JAR file (org.apache.bval.bundle) and ELF Class can tell us that hacker is able to conduct the arbitrary code execution through the Class Parameter passed To the GetClass vulnerability in the Apache Commons BeanUtils library. And therefore we suggest to do the patching immediately. For more details, please refer to following url: https://kb.vmware.com/s/article/79091

an issue was discovered in smartbear readyapi soapui pro 3.2.5 (20th May 2020)

Preface: SmartBear ReadyAPI and SoapUI are automated testing tools that you can use to create functional and security tests for web service APIs. The easiest way to run ReadyAPI tests from Azure DevOps is to use the SoapUI Pro for Azure DevOps task.

Background: The ReadyAPI platform accelerates functional, security and load testing of RESTful, SOAP, GraphQL and other web services right inside the CI/CD pipeline. The DevOps team is no stranger.

Vulnerability details: The security expert found a possible way to conduct cyber attack. When a insider threat occurs. The threat prepatrator can be figure out the target license setup condition. If victim deployed remote floating license setup by ReadyAPI. They will exploit the design weakness for Licensing Server. Since the communications in between SmartAPI and license server is using Java RMI protocol on port 1099 but without transport security. Meanwhile, Java RMI, and the underlying JRMP protocol, relies on Java serialization to transport method arguments, return values and exception data intensively. And therefore the problem is that there’s no way to know what you’re deserializing before you’ve decoded it. So an attacker can serialize a bunch of malicious objects and send them to your application.

Remedy: Allow deserialization, but make it impossible for attackers to create instances of arbitrary classes.
For instance: limit the input to a maximum of 10 embedded objects and 50 bytes of input. Besides, the official remedy solution not release yet.

Remedy on CVE-2020 -11651, CVE-2020 -11652 VMware vRealize Operations Manager addresses Authentication Bypass and Directory Traversal vulnerabilities – 12th May 2020

Preface: If application do not defenses against directory traversal attacks, so an attacker can request the following URL: hxxp://xxx[.]com/loadImage?filename=../../../etc/passwd

Vulnerability details: The VMware Application Remote Collector (ARC) introduced with vRealize Operations Manager 7.5 can integrate with Salt (SaltStack). However the vulnerabilities (CVE-2020-11651 and CVE-2020-11652) found in saltstack this month will be impact VMware operation simultaneously. The impact causes by SaltStack causes VMware vRealize Operations Manager (vROps) vulnerable to Directory traversal vulnerability. Meanwhile it has possiblites to happen critical impact (authentication bypass). For details, please refer to follow official announcement url. https://kb.vmware.com/s/article/79031

Observation: From technical point of view, the design weakness of salt open TCP port 4505 and 4506 on behalf of service daemon. So attacker can be inject command in this part without authentication.

SaltStack has released a security update to address critical vulnerabilities affecting Salt versions prior to 2019.2.4 and 3000.2 (1st May 2020)

Product background: If you have one hundred servers, so it makes sense to use Puppet(open source DevOps systems management tool)for centralizing and automating the configuration management process. SaltStack itself is an open source infrastructure centralized management platform. Compared with other commercial products, its deployment and configuration are slightly more complicated.

Vulnerability details: SaltStack has released a security update to address critical vulnerabilities affecting Salt versions prior to 2019.2.4 and 3000.2. A remote attacker could exploit these vulnerabilities to take control of an affected system. For more details, please refer to attached diagram. The official announcement can be found here. https://docs.saltstack.com/en/latest/topics/releases/3000.2.html

Recommendation:

1. Upgrade SaltStack to a recommended version. It is recommended to take a snapshot backup before upgrading.

2. Set the Salt Master’s default listening ports (default 4505 and 4506) to prohibit opening to the public network, or only to trusted objects.

Take care, data center administrators.

Alert users that a previously disclosed Oracle WebLogic Server remote code execution vulnerability (CVE-2020-2883) is being exploited in the wild. (3rd May 2020)

Preface: Perhaps my alert late for 3 days, but the specify vulnerability hide himself in webLogic product for few years!

Vulnerability details: Alert users that a previously disclosed Oracle WebLogic Server remote code execution vulnerability (CVE-2020-2883) is being exploited in the wild. You can read the official announcement in following link – https://blogs.oracle.com/security/apply-april-2020-cpu

One of the exploit methods – The attacker can locate all of the objects by packet capture. For more details, please refer to attached diagram for reference. As a result, the attacker can replace these objects with his malicious payload. Since the server receives the data and unpacks (deserializes) without integrity check. And therefore it let attacker execute the malicious code on the underlying WebLogic core, allowing the attacker to take control over unpatched systems.

VMware ESXi patches address Stored Cross-Site Scripting (XSS) vulnerability (CVE-2020-3955) – 28th Apr 2020

Preface: Perhaps when you do the web scan or web penetration test. XSS will be easy to find out. However people has contempt this matter.

How to avoid XSS happen?

1. Input should filter characters especially < > & ‘ ” .

2. Whitelisting and input validation are more commonly associated with SQL injection, they can also be used as an additional method of prevention for XSS.

3. Sanitizing user input.

About CVE-2020-3955: For whom with access to modify the system properties of a virtual machine from inside the guest os (such as changing the hostname of the virtual machine) may be able to inject malicious script which will be executed by a victim’s browser when viewing this virtual machine via the ESXi Host Client.

Remedy: VMware official announcement – https://www.vmware.com/security/advisories/VMSA-2020-0008.html