CVE-2026-48860

Summary

Reliance on IP Address for Authentication vulnerability in Erlang/OTP ssl (inet_tls_dist module) allows unauthenticated bypass of the distribution-over-TLS LAN allowlist.

The inet_tls_dist:check_ip/1 function, which enforces a LAN allowlist for Erlang distribution over TLS, calls inet:sockname/1 instead of inet:peername/1 to obtain the peer's IP address. Because inet:sockname/1 returns the local socket address, both the local IP and the supposed peer IP resolve to the same value, causing the subnet mask comparison to always succeed regardless of the actual remote address. Any holder of a CA-signed TLS certificate can therefore bypass the LAN restriction and gain full Erlang distribution access to the node, including rpc:call/4 and code:load_binary/3.

This vulnerability is associated with program file lib/ssl/src/inet_tls_dist.erl.

This issue affects OTP from OTP 26.0 before 29.0.2, 28.5.0.2 and 27.3.4.13 corresponding to ssl from 11.0 before 11.7.2, 11.6.0.2 and 11.2.12.9.

Affected Software

VendorProductVersion RangeStatus
ErlangOTP11.0 < *affected
ErlangOTP26.0 < *affected
ErlangOTP7a08c5507862a7011568506d0c17b1fdef30bee4 < 0209a6df65d605552b378273027b3968b35f26b4affected

Weaknesses

  • CWE-1025: CWE-1025 Comparison Using Wrong Factors
  • CWE-863: CWE-863 Incorrect Authorization

Workarounds

Implement a custom verify_fun SSL option that correctly checks the peer IP address using inet:peername/1 on the socket.

ADP Enrichment

CISA ADP Vulnrichment

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

References