CVE-2025-34468

Summary

libcoap versions up to and including 4.3.5, prior to commit 30db3ea, contain a stack-based buffer overflow in address resolution when attacker-controlled hostname data is copied into a fixed 256-byte stack buffer without proper bounds checking. A remote attacker can trigger a crash and potentially achieve remote code execution depending on compiler options and runtime memory protections. Exploitation requires the proxy logic to be enabled (i.e., the proxy request handling code path in an application using libcoap).

Affected Software

VendorProductVersion RangeStatus
libcoaplibcoap0 <= 4.3.5affected
libcoaplibcoap30db3eaa1f0464722ebea2ca2d5084aebfbd344dunaffected

Weaknesses

  • CWE-121: CWE-121 Stack-based Buffer Overflow

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References