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Arbitrary Code Execution Vulnerabilities in MuPDF Identified and Patched
Talos is disclosing the presence of two vulnerabilities in the Artifex MuPDF renderer. MuPDF is a lightweight PDF parsing and rendering library featuring high fidelity graphics, high speed, and compact code size which makes it a fairly popular PDF library for embedding in different projects, especially mobile and web applications. Both of these vulnerabilities, if exploited, could lead to arbitrary code execution of an attacker’s choice on the target device. Both of these vulnerabilities have been responsibly disclosed and Artifex has released software updates to address these vulnerabilities.
Vulnerability Details
Two memory corruption vulnerabilities exist within Artifex MuPDF render that could result in arbitrary code execution if exploited. These two vulnerabilities manifest as a result of improperly parsing and handling parts of a PDF file.
Player 3 Has Entered the Game: Say Hello to ‘WannaCry’
This post was authored by Martin Lee, Warren Mercer, Paul Rascagneres, and Craig Williams.
Executive Summary
A major ransomware attack has affected many organizations across across the world reportedly including Telefonica in Spain, the National Health Service in the UK, and FedEx in the US. The malware responsible for this attack is a ransomware variant known as ‘WannaCry’.
The malware then has the capability to scan heavily over TCP port 445 (Server Message Block/SMB), spreading similar to a worm, compromising hosts, encrypting files stored on them then demanding a ransom payment in the form of Bitcoin.
Organizations should ensure that devices running Windows are fully patched and deployed in accordance with best practices. Additionally, organizations should have SMB ports (139, 445) blocked from all externally accessible hosts.
Please note this threat is still under active investigation, the situation may change as we learn more or as our adversary responds to our actions. Talos will continue to actively monitor and analyze this situation for new developments and respond accordingly. As a result, new coverage may be developed or existing coverage adapted and/or modified at a later date. For comments and questions, please follow the link below to the Talos Intelligence blog, comments here have been closed to keep conversation in one forum. For current information, please refer to your Firepower Management Center or Snort.org.
Threat Round-up for May 05 – May 12
Today, Talos is publishing a glimpse into the most prevalent threats we’ve observed between May 05 and May 12. As with previous round-ups, this post isn’t meant to be an in-depth analysis. Instead, this post will summarize the threats we’ve observed by highlighting key behavior characteristics, indicators of compromise, and how our customers are automatically protected from these threats.
As a reminder, the information provided for the following threats in this post is non-exhaustive and current as of date of publication. Detection and coverage for the following threats is subject to updates pending additional threat or vulnerability analysis. For the most current information, please refer to your FireSIGHT Management Center, Snort.org, or ClamAV.net.
Jaff Ransomware: Player 2 Has Entered The Game
This post was written by Nick Biasini, Edmund Brumaghin and Warren Mercer with contributions from Colin Grady
Summary
Talos is constantly monitoring the email threat landscape and tracking both new threats as well as changes to existing threats. We recently observed several large scale email campaigns that were attempting to distribute a new variant of ransomware that has been dubbed “Jaff”. Interestingly we identified several characteristics that we have previously observed being used during Dridex and Locky campaigns. In a short period of time, we observed multiple campaigns featuring high volumes of malicious spam emails being distributed, each using a PDF attachment with an embedded Microsoft Word document functioning as the initial downloader for the Jaff ransomware. While Cisco customers were already automatically protected against this threat, we decided to take a deeper look at this threat and its possible implications across the threat landscape. We have outlined the infection process and additional relevant information regarding this threat in detail below.
Vulnerability Spotlight: Hangul Word Processor Remote Code Execution Vulnerability
Talos is disclosing the presence of a vulnerability in Hangul Word Processor. Published by Hancom inc. the Hangul Office Suite, of which Hangul Word Processor is part, is the leading word processing and office productivity suite in South Korea. This vulnerability allows attackers to craft a malicious document that when opened, allows the attacker to cause arbitrary code to be executed on the victim’s system.
Microsoft Patch Tuesday – May 2017
Today, Microsoft has release their monthly set of security updates designed to address vulnerabilities. This month’s release addresses 56 vulnerabilities with 15 of them rated critical and 41 rated important. Impacted products include .NET, DirectX, Edge, Internet Explorer, Office, Sharepoint, and Windows.
In addition to the coverage Talos is providing for the normal monthly Microsoft security advisories, Talos is also providing coverage for CVE-2017-0290, the MsMpEng Malware Protection service vulnerability in Windows reported by Natalie Silvanovich and Tavis Ormandy of Google Project Zero. Snort rule SIDs for this specific vulnerability are 42820-42821.
Vulnerability Spotlight: WolfSSL library X509 Certificate Text Parsing Code Execution Vulnerability
Discovered by Aleksandar Nikolic of Cisco Talos
Overview
Talos is disclosing TALOS-2017-0293 / CVE 2017-2800, a code execution vulnerability in WolfSSL. WolfSSL is a lightweight SSL/TLS library targeted specifically for embedded and RTOS (Real-Time Operating System) environments, due largely to its small size and performance. WolfSSL is used in a wide range of products including ICS and IoT devices.
This particular vulnerability is related to the use of x.509 certificates and the code that deals with string fields in DER certificates. Specifically the code responsible for parsing ‘commonName’, ‘countryName’, ‘localityName’, ‘stateName’, ‘orgName’, and ‘orgUnit’. A specially crafted x.509 certificate can cause a single out-of-bounds overwrite that could result in certificate validation issues, denial of service, or remote code execution. To trigger this vulnerability, the adversary needs to supply a malicious x.509 certificate to either the server or client application that is making use of this library. The full details surrounding the vulnerability are available here.
Vulnerability Spotlight: Power Software PowerISO ISO Code Execution Vulnerabilities
These vulnerabilities were discovered by Piotr Bania of Cisco Talos.
Today, Talos is releasing details of a new vulnerability discovered within the Power Software PowerISO disk imaging software. TALOS-2017-0318 and TALOS-2017-0324 may allow an attacker to execute arbitrary code remotely on the vulnerable system when a specially crafted ISO image is opened and parsed by the PowerISO software.
Overview
The vulnerabilities are present in the Power Software PowerISO disk imaging utility, used by Windows users to create, edit, mount and convert various popular disk image file formats. The software is commonly used by home users to mount ISO disk images since this capability is not included by default in Windows versions prior to version 8.
ISO (9660) disk image format is a file system within a single file. Essentially, it is a binary copy of the file system used by the standard software CD-ROM installation disks. Today, most of the installation disks for popular software and operating systems are distributed using the ISO file format.
Vulnerability Spotlight: AntennaHouse DMC Library Arbitrary Code Execution Flaws
These vulnerabilities were discovered by Marcin ‘Icewall’ Noga of Talos.
Today, Talos is disclosing several vulnerabilities that have been identified in the AntennaHouse DMC library which is used in various products for web-based document searching and rendering. These vulnerabilities manifest as a failure to correctly parse Microsoft Office documents and could be exploited to achieve arbitrary code execution. These vulnerabilities are being disclosed in coordination with AntennaHouse.
Vulnerability Details
Multiple heap corruption vulnerabilities exist within AntennaHouse DMC HTMLFilter that could be exploited to achieve arbitrary code execution on the targeted machine. These vulnerabilities manifest due to improper handling of Microsoft Office documents, such as Word and PowerPoint files. An adversary that passes a specifically crafted document to the converter could exploit one of these vulnerabilities. Note that the method that an adversary could compromise a vulnerable machine varies as this library is known to be incorporated into other third-party products.
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