Original release date: April 29, 2015
Systems Affected
Systems running unpatched software from Adobe, Microsoft, Oracle, or OpenSSL.
Overview
Cyber threat actors continue to exploit unpatched software to conduct attacks against critical infrastructure organizations. As many as 85 percent of targeted attacks are preventable [1].
This Alert provides information on the 30 most commonly exploited vulnerabilities used in these attacks, along with prevention and mitigation recommendations.
It is based on analysis completed by the Canadian Cyber Incident Response Centre (CCIRC) and was developed in collaboration with our partners from Canada, New Zealand, the United Kingdom, and the Australian Cyber Security Centre.
Description
Unpatched vulnerabilities allow malicious actors entry points into a network. A set of vulnerabilities are consistently targeted in observed attacks.
Impact
A successful network intrusion can have severe impacts, particularly if the compromise becomes public and sensitive information is exposed. Possible impacts include:
- Temporary or permanent loss of sensitive or proprietary information,
- Disruption to regular operations,
- Financial losses relating to restoring systems and files, and
- Potential harm to an organization’s reputation.
Solution
Maintain up-to-date software
The attack vectors frequently used by malicious actors such as email attachments, compromised “watering hole” websites, and other tools often rely on taking advantage of unpatched vulnerabilities found in widely used software applications. Patching is the process of repairing vulnerabilities found in these software components.
It is necessary for all organizations to establish a strong ongoing patch management process to ensure the proper preventive measures are taken against potential threats. The longer a system remains unpatched, the longer it is vulnerable to being compromised. Once a patch has been publicly released, the underlying vulnerability can be reverse engineered by malicious actors in order to create an exploit. This process has been documented to take anywhere from 24-hours to four days. Timely patching is one of the lowest cost yet most effective steps an organization can take to minimize its exposure to the threats facing its network.
Patch commonly exploited vulnerabilities
Executives should ensure their organization’s information security professionals have patched the following software vulnerabilities. Please see patching information for version specifics.
Implement the following four mitigation strategies.
As part of a comprehensive security strategy, network administrators should implement the following four mitigation strategies, which can help prevent targeted cyber attacks.
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Ranking
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Mitigation Strategy
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Rationale
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1
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Use application whitelisting to help prevent malicious software and unapproved programs from running.
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Application whitelisting is one of the best security strategies as it allows only specified programs to run, while blocking all others, including malicious software.
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2
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Patch applications such as Java, PDF viewers, Flash, web browsers and Microsoft Office.
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Vulnerable applications and operating systems are the target of most attacks. Ensuring these are patched with the latest updates greatly reduces the number of exploitable entry points available to an attacker.
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3
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Patch operating system vulnerabilities.
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4
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Restrict administrative privileges to operating systems and applications based on user duties.
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Restricting these privileges may prevent malware from running or limit its capability to spread through the network.
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It is recommended that users review US-CERT Security Tip (ST13-003) and CCIRC’s Mitigation Guidelines for Advanced Persistent Threats for additional background information and to assist in the detection of, response to, and recovery from malicious activity linked to advance persistent threats [2, 3].
References
Revision History
- April 29, 2015: Initial release
This product is provided subject to this Notification and this Privacy & Use policy.
Source: US-CERT Alerts
