As cyber threats become ever more sophisticated and targeted towards businesses, having a large attack surface greatly amplifies an organization‘s security risks. From complex malware to insider threats to social engineering tactics – attackers today have numerous vectors to infiltrate a company‘s systems and cause damage. Therefore, CISOs and security leaders must make minimizing the attack surface a key priority in their security programs.
What is an Attack Surface and Why Care About it?
In simple terms, a system‘s attack surface refers to the total number of vulnerabilities or entry points that an adversary can exploit to compromise that system. It encompasses the "surface area" exposed on networks, endpoints, applications, users and physical spaces which malicious actors can target to breach security defenses.
Attack surfaces come in three main flavors:
Network attack surface – Open ports, insecure protocols, misconfigurations etc.
Physical attack surface – Doors, perimeter fencing, employee devices at home locations etc.
Social engineering attack surface – Users susceptible to phishing, pretexting, impersonation tactics etc.
Having a large attack surface hands the advantage to attackers, allowing them multiple opportunities to infiltrate an organization. It‘s akin to fortifying a castle – the more breaches and cracks in your walls, the easier it is for enemies to take over. Conversely, shrinking your attack surface closes those security gaps and makes you a hardened target.
Businesses today depend heavily on technology, have distributed workforce and supply chains, and store valuable data – making them lucrative targets. Without control over the attack surface, they remain highly vulnerable in an evolving threat landscape. Recent research shows that over 80% of breaches leverage some vulnerability that is known and patchable. Attack surfaces and security costs have risen over 200% in the last 5 years due to digital transformation.
Steps must be taken proactively to limit exposure and prevent incidents. According to metrics, a 5% decrease in attack surface leads to around 30% fewer security incidents.
Mapping Out Your Organization‘s Attack Surface
The first step towards reducing risk is identifying what needs protection in the first place. Organizations should thoroughly analyze their environment to create an inventory of assets, accounts, data flows etc. and pinpoint areas of concern.
Documenting Hardware and Software Assets
Make a checklist of all physical devices and technology systems connected to your environment. This includes servers, endpoints, network devices, IoT systems, cloud platforms, etc. Note down hardware makes/models, OS versions and installed software.
You want clarity on exactly what systems exist, where they reside, their function and the type of data they process. Any gaps here can blindside you later. Attack graph analysis can help model dependencies and interactions between systems to identify hidden risks.
Mapping Out Network Architecture and Connections
Network topology blueprints showing how everything connects together are invaluable. Determine trust boundaries between network zones, what systems have internet access, where remote access points exist – essentially data/access flows in/out of the organization.
This allows you to spot unchecked connections that attackers could leverage as pathways inside. Common issues like over-permissive firewalls, accessible admin interfaces or insecure remote access all expand the attack surface.
Auditing Accounts, Credentials and Privileges
Enumerate user accounts across all systems, especially privileged ones like domain admins. Document signing protocols for access requests. Understand password policies applied across the environment.
Poor account hygiene like bad passwords, stale accounts or hand-ing out excessive user rights all weaken security. Insider and compromised account risks account for over 30% of reported incidents.
Locating Sensitive Data
Make note of where Crown Jewel data like customer PII, financial records or intellectual property reside. On endpoints? Database servers? Cloud platforms? Understanding sensitivity levels and data types can inform protection efforts for high value assets. Over 80% of data breaches target customer and employee data.
Interviewing Departments
Get perspectives from individual teams on ground realities. What systems do they operate? Who do they share data with? What third-party tools do they use? What security training have they received?
They might reveal use of shadow IT or other unmanaged assets missing from official documentation.
Incorporating Third Parties/Vendors
Don‘t restrict your review to just internal environment. Cloud providers, contractors, supply chain partners – where relevant – should also be assessed on security posture as they may interface with sensitive systems or data at some point.
Cast a wide net here for risks like misconfigured cloud storage or unvetted vendor access to be uncovered. Research shows over 65% of businesses suffered a breach due to a vendor vulnerability.
Leveraging Data Science Approaches
Data science approaches like analyzing syslog or NetFlow records using machine learning algorithms can effectively highlight anomalies in asset communicatiions and user activity.
Applied to attack surface management, these techniques can reveal suspicious new connections or access attempts – such as unauthorized devices, inbound traffic from suspicious IPs or abnormal data transfers – that point to hidden risks.
Documenting the above will help establish scope of IT infrastructure and reveal potential weak links to address.
Prioritizing Fixes for Most Critical Risks
With visibility into the attack surface, systematically analyze threats and vulnerabilities against identified assets to determine specific risks to the organization. Assign risk scores based on factors like likelihood of exploit, impact to operations or data loss.
Focus first on plugging gaps in publicly facing systems, servers holding sensitive data and endpoints used by senior leadership as those pose greater consequences if compromised – both monetary and reputationally. Similarly prioritize remediation based on type of vulnerability – an unpatched server or open firewall needs fixing before misconfigurations that have milder impact.
According to analysis, vulnerabilities left unaddressed for over 30 days have around 80% probability of being exploited by adversaries.
Buy-in can be secured from management by quantifying financial losses expected due to high probability risks. Attach metrics showing value of securing those points versus leaving them be. Expected losses up to $200,000 per day can be realistically expected in case of successful ransomware or data breach attacks as per insustry data.
Shrinking the Network Attack Surface
With networks being fundamental to operations today, locking them down is imperative:
Perform external penetration tests to check if perimeter defenses can be breached from outside. Mimic real attacks – exploit open ports, try bypassing firewalls, probe edge servers for unpatched software etc.
Harden systems against common attack vectors like disabling unnecessary ports/features, removing default accounts/passwords, restricting management interface access etc.
Assess firewall rules to ensure only traffic essential for business is allowed while blocking malicious protocols/IP addresses. Segment your network into zones based on trust levels – with restricted connectivity between zones.
Implement microsegmentation for sensitive applications – where apps are isolated from rest of network via programmable policy enforcement points. This arrests lateral movement.
Adopt Zero Trust model to enforce verification of identity, device health and authorization context before granting any network requests. This limits lateral movement inside the network by malware or malicious insiders. Over 50% of organizations have zero trust on roadmap due to its attack surface benefits.
Monitor for data exfiltration attempts using ML-powered data loss prevention tools that perform deep packet inspection to detect unauthorized transfers and connector usage.
Assess cloud attack surface by inventorying resources, checking data flows between services, reviewing IAM permissions etc. Cloud platforms have their own set of risks – like data leaks due to misconfigurations or unauthorized access.
Safeguarding Physical Assets and Spaces
While digital risks get more attention, physical attack vectors cannot be ignored given the damage they enable. 31% of cyberattacks involve physical access in some form. Some mitigations include:
Enforce facility access control via biometrics, RFID card readers, ID badges, security cameras, guards etc. Limit access to sensitive areas like server rooms or filing cabinets to only personnel needing it.
Create secure spaces for storing physical data copies, equipment meant for disposal etc. Use enumerated asset tags that make theft more noticeable.
Issue laptop/mobile device encryption to prevent theft of confidential data. Enforce strong locks/cables for securing devices in public places.
Educate personnel on piggybacking risks – deliberately or unconsciously letting in unapproved individuals alongside them. Policies restricting badging of unknown persons.
Implement clean desk policies mandating sensitive paperwork like customer orders, business plans etc. to not lie openly accessible overnight. Enforce screen locks on workstations when unattended for over 10 minutes.
Combating Social Engineering Risks
Despite extensive technical controls, staff getting manipulated via social engineering remains a stubborn threat. Common tactics like phishing emails, vishing calls or impersonators exploit human tendencies to bypass security systems. Combat this by:
Conducting periodic simulated phishing and vishing campaigns to test employee responses and train them on spotting red flags. Customize attacks to leverage shortcomings found earlier.
Establish KPIs like percentage of users falling for phishing tests to quantify improvements over time. Benchmark against industry averages.
Implement security orchestration playbooks that immediately disable compromised user accounts that click malicious links as detected by SOAR tooling.
Institute password policies like banned sequences, mandatory 2FA etc. that are resilient against password reuse across personal/professional accounts, cracking or sharing risks.
Over 80% of breaches exploit compromised credentials.
Promote awareness on latest social engineering tactics so employees stay vigilant to suspicious communications,Such asLike cautioning departments more prone to business email compromise attacks.
Limit public disclosure as adversaries can leverage details like organization structure, technologies used etc. from websites or social media to refine attacks.
Continuous assessment and improvement of human readiness is essential here – accounting for over 20% of attack surface.
Implementing Attack Surface Management
While the above steps help shrink attack surface, the picture is constantly evolving due to workforce mobility, cloud migrations and new regulations. To lockdown defenses for the long term:
Establish attack surface management program with quarterly audits, threat modeling, risk quantification etc. as a recurring activity. New assets get discovered, software deteriorates, credentials expire and configurations change – requiring periodic reviews.
Leverage attack surface measurement tools that provide quantifiable metrics/scores on gaps discovered and progress in surface reduction. Trends reveal what areas need investment.
Perform red team exercises mimicking advanced real world attacks by bypassing defenses. Blue team defends while red team penetrates. Uncover operational shortcomings.
Invest in automated policy compliance tools that continuously check for misconfigurations, unpatched systems, unauthorized software etc. against security baselines – freeing up staff.
Monitor vendor/partner environments as much as feasible via questionnaires, certifications and standards like SIG or CSA to ensure security keeps pace with expanding ecosystem.
Incentivize teams like helpdesk, SOC, engineering etc. that often detect attack surface threats like compromised user accounts, malware infections or unauthorized devices to report them through rewards programs or recognition initiatives.
The metrics gathered and visibility achieved through these efforts pays dividends in keeping control over the evolving attack surface.
Leverage Attack Surface Measurement Frameworks
Structured frameworks help quantify and benchmark attack surface exposure over time:
_Source: https://cwe.mitre.org/documents/being_quantitative/index.html_
Implement Attack Surface Review Boards
Dedicated councils that govern attack surface monitoring and remediation activities across on-prem and cloud environments. Cross-functional teams examine risks, verify fixes and approve new exposures.
The Last Word on Minimizing Attack Surface
In today‘s complex technology environments, eliminating the attack surface completely is impossible. However, organizations cannot afford to resign themselves to a large exposure either due to the detrimental business impact of breaches. Reducing your organization‘s attack surface is thus an indispensable security practice requiring executive backing.
While securing every single system and social vulnerability takes enormous effort, going after obvious gaps and risks posing real financial and reputational threats is sensible. Measuring improvements also helps justify investments, be it in terms of training for safer human behavior or upgraded firewalls for locking down internet access.
With constant vigilance and a multi-pronged approach, risks can be effectively countered even as more sophisticated threats emerge. The time, effort and budget for shrinking attack surface is well warranted by the ensuing peace of mind.
