CVE intelligence and bounded remediation

CVE-2021-34730 — Cisco Application Extension Platform security vulnerability

Critical CVSS 9.8

A vulnerability in the Universal Plug-and-Play (UPnP) service of Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers could allow an unauthenticated, remote attacker to execute arbitrary code or cause an affected device to restart unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of incoming UPnP traffic. An attacker could exploit this vulnerability by sending a crafted UPnP request to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system or cause the device to reload, resulting in a DoS condition. Cisco has not released software updates that address this vulnerability.

Severity
Critical
CVSS
9.8 (3.1)
Published
2021-08-18
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-121, CWE-787

Affected products

  • cisco / application_extension_platform / 1.0.3.55
  • cisco / rv110w_wireless-n_vpn_firewall_firmware
  • cisco / rv130_vpn_router_firmware
  • cisco / rv130w_wireless-n_multifunction_vpn_router_firmware
  • cisco / rv215w_wireless-n_vpn_router_firmware

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

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Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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