CyberRota Analysis
AI-GeneratedThe vulnerability affects the luci-lib-px5g package in OpenWrt, specifically in the ASN.1 encoding routine used for signing certificates with 2040-bit RSA keys, leading to a heap-based buffer overflow. This flaw can potentially allow an attacker to execute arbitrary code, depending on the embedding application, making it critical for users of OpenWrt versions 18.06 to 25.12 to prioritize patching or upgrading their systems. Organizations utilizing these versions, especially those exposing the Lua interface, should assess their risk and apply mitigations promptly.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
luci-lib-px5g (LuCI) contains a heap-based buffer overflow in the native ASN.1 encoding routine asn1_add_obj (x509write.c) when signing a certificate with a 2040-bit RSA key. For a 255-byte signature, the BIT STRING allocation is computed from the DER length encoding of 255 bytes, but the payload written after prepending the unused-bits byte is 256 bytes, requiring one additional DER length octet. As a result the allocation is 259 bytes while the tag, length, unused-bits byte, and signature require 260 bytes, and the final memcpy writes one byte beyond the heap buffer. The overflow is reachable through the exported Lua interface via create_selfsigned(); whether it is remotely exploitable depends on the embedding application. The vulnerable code is present on the openwrt-18.06 through openwrt-25.12 release branches and is absent from master, where the luci-lib-px5g package has been removed rather than patched.