ubuntu-cve-2026-45537
Vulnerability from osv_ubuntu
Published
2026-08-04 23:16
Modified
2026-08-04 23:16
Summary
Details

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. In versions prior to 3.6.6 and 4.0.0-rc1, the construct_uri() function concatenates multiple URI components (protocol, username, domain, port, params) into a fixed 1024-byte global BSS buffer without any bounds checking. When a routing script calls construct_uri() with an attacker-controlled username, a combined component length exceeding 1024 bytes overflows the buffer, corrupting adjacent global data with attacker-controlled content. The overflow reaches disable_503_translation, a global flag controlling SIP 503 response handling, allowing an attacker to deterministically set the flag via the URI username and alter the server's routing behavior for subsequent messages. Because the same buffer is shared with contact_builder(), the overflow also corrupts that function's data, and without a memory sanitizer the adjacent globals are silently overwritten on every request containing a long username. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.

Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "opensips",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-b2bua-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-berkeley-bin",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-berkeley-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-carrierroute-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-compression-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-console",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-cpl-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-dbhttp-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-dialplan-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-emergency-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-geoip-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-http-modules",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-identity-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-jabber-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-json-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-ldap-modules",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-lua-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-memcached-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-mysql-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-perl-modules",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-postgres-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-presence-modules",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-rabbitmq-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-radius-modules",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-redis-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-regex-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-restclient-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-sctp-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-snmpstats-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-sqlite-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-tls-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-tlsmgm-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-unixodbc-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-wss-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-xmlrpc-module",
            "binary_version": "2.2.2-3build4"
          },
          {
            "binary_name": "opensips-xmpp-module",
            "binary_version": "2.2.2-3build4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "opensips",
        "purl": "pkg:deb/ubuntu/opensips@2.2.2-3build4?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.2.2-3build2",
        "2.2.2-3build3",
        "2.2.2-3build4"
      ]
    }
  ],
  "aliases": [],
  "details": "OpenSIPS is a Session Initiation Protocol (SIP) server implementation. In versions prior to 3.6.6 and 4.0.0-rc1, the construct_uri() function concatenates multiple URI components (protocol, username, domain, port, params) into a fixed 1024-byte global BSS buffer without any bounds checking. When a routing script calls construct_uri() with an attacker-controlled username, a combined component length exceeding 1024 bytes overflows the buffer, corrupting adjacent global data with attacker-controlled content. The overflow reaches disable_503_translation, a global flag controlling SIP 503 response handling, allowing an attacker to deterministically set the flag via the URI username and alter the server\u0027s routing behavior for subsequent messages. Because the same buffer is shared with contact_builder(), the overflow also corrupts that function\u0027s data, and without a memory sanitizer the adjacent globals are silently overwritten on every request containing a long username. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.",
  "id": "UBUNTU-CVE-2026-45537",
  "modified": "2026-08-04T23:16:00Z",
  "published": "2026-08-04T23:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-45537"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-45537"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/OpenSIPS/opensips/commit/4d23613b65579b073784a07a65d3bf52443a4efb"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/OpenSIPS/opensips/commit/5f103effaf5f372cccffe0b138f16998eba12668"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/OpenSIPS/opensips/security/advisories/GHSA-v7h4-fwrc-c66v"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-45537"
  ]
}



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