CVE intelligence and bounded remediation

CVE-2016-6356 — Cisco Email Security Appliance security vulnerability

High CVSS 7.8

A vulnerability in the email message filtering feature of Cisco AsyncOS Software for Cisco Email Security Appliances could allow an unauthenticated, remote attacker to cause an affected device to stop scanning and forwarding email messages due to a denial of service (DoS) condition. Affected Products: This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for Cisco Email Security Appliances, both virtual and hardware appliances, if the software is configured to apply a message filter or content filter to incoming email attachments. The vulnerability is not limited to any specific rules or actions for a message filter or content filter. More Information: CSCuz63143. Known Affected Releases: 8.5.7-042 9.7.0-125. Known Fixed Releases: 10.0.0-125 9.1.1-038 9.7.2-047.

Severity
High
CVSS
7.8 (2.0)
Published
2016-10-28
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-20

Affected products

  • cisco / email_security_appliance / 3.3.1-09
  • cisco / email_security_appliance / 7.1.0
  • cisco / email_security_appliance / 7.1.1
  • cisco / email_security_appliance / 7.1.2
  • cisco / email_security_appliance / 7.1.3
  • cisco / email_security_appliance / 7.1.4

Showing 6 representative product identities from 56 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

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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