CVE intelligence and bounded remediation

CVE-2020-14935 — Buffer overflows were discovered in Contiki-NG 4.4 through 4.5, in the SNMP bulk get request response encoding function

Critical CVSS 9.8

Buffer overflows were discovered in Contiki-NG 4.4 through 4.5, in the SNMP bulk get request response encoding function. The function parsing the received SNMP request does not verify the input message's requested variables against the capacity of the internal SNMP engine buffer. When a bulk get request response is assembled, a stack buffer dedicated for OIDs (with a limited capacity) is allocated in snmp_engine_get_bulk(). When snmp_engine_get_bulk() is populating the stack buffer, an overflow condition may occur due to lack of input length validation. This makes it possible to overwrite stack regions beyond the allocated buffer, including the return address from the function. As a result, the code execution path may be redirected to an address provided in the SNMP bulk get payload. If the target architecture uses common addressing space for program and data memory, it may also be possible to supply code in the SNMP request payload, and redirect the execution path to the remotely injected code, by modifying the function's return address.

Severity
Critical
CVSS
9.8 (3.1)
Published
2020-08-18
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-787

Affected products

  • contiki-ng / contiki-ng

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

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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