CVE intelligence and bounded remediation
CVE-2022-20943 — Cisco Firepower Threat Defense security vulnerability
Multiple vulnerabilities in the Server Message Block Version 2 (SMB2) processor of the Snort detection engine on multiple Cisco products could allow an unauthenticated, remote attacker to bypass the configured policies or cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to improper management of system resources when the Snort detection engine is processing SMB2 traffic. An attacker could exploit these vulnerabilities by sending a high rate of certain types of SMB2 packets through an affected device. A successful exploit could allow the attacker to trigger a reload of the Snort process, resulting in a DoS condition. Note: When the snort preserve-connection option is enabled for the Snort detection engine, a successful exploit could also allow the attacker to bypass the configured policies and deliver a malicious payload to the protected network. The snort preserve-connection setting is enabled by default. See the Details ["#details"] section of this advisory for more information. Note: Only products that have Snort 3 configured are affected. Products that are configured with Snort 2 are not affected.
- Severity
- Medium
- CVSS
- 5.8 (3.1)
- Published
- 2022-11-15
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-244
Affected products
- cisco / firepower_threat_defense / 7.0.0
- cisco / firepower_threat_defense / 7.0.0.1
- cisco / firepower_threat_defense / 7.0.1
- cisco / firepower_threat_defense / 7.0.1.1
- cisco / cyber_vision / 3.0.0
- cisco / cyber_vision / 3.0.1
Matched remediation archetype
Resource exhaustion and denial of service
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
- Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
- Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.
Remediate safely
- Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
- Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
- Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.
Authoritative sources
Complete CVE record and remediation plan
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