Source: #_shellntel Blog Author: unknown URL: https://blog.shellntel.com/p/using-rpc-filters-to-protect-against-coercion-attacks
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ONE SENTENCE SUMMARY: Coercion attacks exploit network vulnerabilities to escalate privileges, requiring comprehensive remediation and detection strategies beyond simple patches or fixes.
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MAIN POINTS:
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Coercion attacks force authentication requests to attacker-specified hosts, often chaining with other exploits.
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Many organizations fail to fully remediate coercion vulnerabilities despite widespread awareness.
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Partial remediation often focuses on ADCS or NTLMv1 downgrading, leaving other attack vectors open.
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RPC filters in Windows can mitigate some coercion attacks but have limitations and bypasses.
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Several well-known coercion vulnerabilities exist, including Printer Bug, PetitPotam, and DFS Coerce.
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Microsoft has patched some vulnerabilities, but others remain exploitable with authenticated access.
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PowerShell scripts can help automate blocking vulnerable RPC endpoints.
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Event IDs like 5145 and 5712 can aid in detecting coercion attack attempts.
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Domain Controllers should not run print spooler services to reduce attack surfaces.
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Effective remediation requires patching, disabling unnecessary services, and implementing robust monitoring.
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TAKEAWAYS:
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Coercion attacks remain a serious privilege escalation threat despite existing mitigations.
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Organizations must implement layered defenses, not just rely on patching.
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PowerShell scripts can streamline RPC endpoint blocking for better security.
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Monitoring Event IDs like 5145 can improve detection of attack attempts.
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Regular security assessments are essential to identify and remediate lingering vulnerabilities.