ubuntu-cve-2025-43857
Vulnerability from osv_ubuntu
Published
2025-04-28 16:15
Modified
2026-07-06 14:07
Summary
Details

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5, there is a possibility for denial of service by memory exhaustion when net-imap reads server responses. At any time while the client is connected, a malicious server can send can send a "literal" byte count, which is automatically read by the client's receiver thread. The response reader immediately allocates memory for the number of bytes indicated by the server response. This should not be an issue when securely connecting to trusted IMAP servers that are well-behaved. It can affect insecure connections and buggy, untrusted, or compromised servers (for example, connecting to a user supplied hostname). This issue has been patched in versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5.

Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
6.0 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
N/A (UNKNOWN)
low
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "jruby",
            "binary_version": "1.5.6-9+deb8u2build0.14.04.1~esm2"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "jruby",
        "purl": "pkg:deb/ubuntu/jruby@1.5.6-9+deb8u2build0.14.04.1~esm2?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.6-5ubuntu1",
        "1.5.6-6",
        "1.5.6-7",
        "1.5.6-9+deb8u2build0.14.04.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "jruby",
            "binary_version": "1.7.22-1ubuntu1"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "jruby",
        "purl": "pkg:deb/ubuntu/jruby@1.7.22-1ubuntu1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.7.21-2ubuntu4",
        "1.7.22-1ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libruby2.5",
            "binary_version": "2.5.1-1ubuntu1.16+esm8"
          },
          {
            "binary_name": "ruby2.5",
            "binary_version": "2.5.1-1ubuntu1.16+esm8"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "ruby2.5",
        "purl": "pkg:deb/ubuntu/ruby2.5@2.5.1-1ubuntu1.16+esm8?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.5.0~preview1-1ubuntu2",
        "2.5.0-4ubuntu1",
        "2.5.0-4ubuntu4",
        "2.5.0-5ubuntu1",
        "2.5.0-6ubuntu1",
        "2.5.1-1ubuntu1",
        "2.5.1-1ubuntu1.1",
        "2.5.1-1ubuntu1.2",
        "2.5.1-1ubuntu1.4",
        "2.5.1-1ubuntu1.5",
        "2.5.1-1ubuntu1.6",
        "2.5.1-1ubuntu1.7",
        "2.5.1-1ubuntu1.8",
        "2.5.1-1ubuntu1.9",
        "2.5.1-1ubuntu1.10",
        "2.5.1-1ubuntu1.11",
        "2.5.1-1ubuntu1.12",
        "2.5.1-1ubuntu1.13",
        "2.5.1-1ubuntu1.14",
        "2.5.1-1ubuntu1.15",
        "2.5.1-1ubuntu1.16",
        "2.5.1-1ubuntu1.16+esm1",
        "2.5.1-1ubuntu1.16+esm3",
        "2.5.1-1ubuntu1.16+esm4",
        "2.5.1-1ubuntu1.16+esm5",
        "2.5.1-1ubuntu1.16+esm6",
        "2.5.1-1ubuntu1.16+esm7",
        "2.5.1-1ubuntu1.16+esm8"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "jruby",
            "binary_version": "9.1.17.0-1~18.04"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "jruby",
        "purl": "pkg:deb/ubuntu/jruby@9.1.17.0-1~18.04?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "9.1.13.0-1",
        "9.1.17.0-1~18.04"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libruby2.7",
            "binary_version": "2.7.0-5ubuntu1.18+esm5"
          },
          {
            "binary_name": "ruby2.7",
            "binary_version": "2.7.0-5ubuntu1.18+esm5"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "ruby2.7",
        "purl": "pkg:deb/ubuntu/ruby2.7@2.7.0-5ubuntu1.18+esm5?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.7.0-1",
        "2.7.0-2",
        "2.7.0-3",
        "2.7.0-4",
        "2.7.0-4ubuntu1",
        "2.7.0-5ubuntu1",
        "2.7.0-5ubuntu1.1",
        "2.7.0-5ubuntu1.2",
        "2.7.0-5ubuntu1.3",
        "2.7.0-5ubuntu1.4",
        "2.7.0-5ubuntu1.5",
        "2.7.0-5ubuntu1.6",
        "2.7.0-5ubuntu1.7",
        "2.7.0-5ubuntu1.8",
        "2.7.0-5ubuntu1.9",
        "2.7.0-5ubuntu1.10",
        "2.7.0-5ubuntu1.11",
        "2.7.0-5ubuntu1.12",
        "2.7.0-5ubuntu1.13",
        "2.7.0-5ubuntu1.14",
        "2.7.0-5ubuntu1.15",
        "2.7.0-5ubuntu1.16",
        "2.7.0-5ubuntu1.17",
        "2.7.0-5ubuntu1.18",
        "2.7.0-5ubuntu1.18+esm1",
        "2.7.0-5ubuntu1.18+esm3",
        "2.7.0-5ubuntu1.18+esm4",
        "2.7.0-5ubuntu1.18+esm5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "jruby",
            "binary_version": "9.1.17.0-3build6"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "jruby",
        "purl": "pkg:deb/ubuntu/jruby@9.1.17.0-3build6?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "9.1.17.0-3",
        "9.1.17.0-3build5",
        "9.1.17.0-3build6"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libruby3.0",
            "binary_version": "3.0.2-7ubuntu2.13"
          },
          {
            "binary_name": "ruby3.0",
            "binary_version": "3.0.2-7ubuntu2.13"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "ruby3.0",
        "purl": "pkg:deb/ubuntu/ruby3.0@3.0.2-7ubuntu2.13?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.2-5ubuntu1",
        "3.0.2-7",
        "3.0.2-7ubuntu2",
        "3.0.2-7ubuntu2.1",
        "3.0.2-7ubuntu2.2",
        "3.0.2-7ubuntu2.3",
        "3.0.2-7ubuntu2.4",
        "3.0.2-7ubuntu2.5",
        "3.0.2-7ubuntu2.6",
        "3.0.2-7ubuntu2.7",
        "3.0.2-7ubuntu2.8",
        "3.0.2-7ubuntu2.10",
        "3.0.2-7ubuntu2.11",
        "3.0.2-7ubuntu2.12",
        "3.0.2-7ubuntu2.13"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "jruby",
            "binary_version": "9.4.6.0+ds-1ubuntu3"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "jruby",
        "purl": "pkg:deb/ubuntu/jruby@9.4.6.0+ds-1ubuntu3?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "9.3.9.0+ds-1",
        "9.4.5.0+ds-1",
        "9.4.5.0+ds-1ubuntu1",
        "9.4.6.0+ds-1ubuntu3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libruby3.2",
            "binary_version": "3.2.3-1ubuntu0.24.04.8"
          },
          {
            "binary_name": "ruby3.2",
            "binary_version": "3.2.3-1ubuntu0.24.04.8"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "ruby3.2",
        "purl": "pkg:deb/ubuntu/ruby3.2@3.2.3-1ubuntu0.24.04.8?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.2.3-1",
        "3.2.3-1build2",
        "3.2.3-1build3",
        "3.2.3-1ubuntu0.24.04.1",
        "3.2.3-1ubuntu0.24.04.3",
        "3.2.3-1ubuntu0.24.04.5",
        "3.2.3-1ubuntu0.24.04.6",
        "3.2.3-1ubuntu0.24.04.7",
        "3.2.3-1ubuntu0.24.04.8"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "jruby",
            "binary_version": "9.4.8.0+ds-3ubuntu1"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "jruby",
        "purl": "pkg:deb/ubuntu/jruby@9.4.8.0+ds-3ubuntu1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
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          ],
          "type": "ECOSYSTEM"
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      ],
      "versions": [
        "9.4.8.0+ds-2ubuntu1",
        "9.4.8.0+ds-3ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libruby3.3",
            "binary_version": "3.3.8-2ubuntu2.1"
          },
          {
            "binary_name": "ruby3.3",
            "binary_version": "3.3.8-2ubuntu2.1"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "ruby3.3",
        "purl": "pkg:deb/ubuntu/ruby3.3@3.3.8-2ubuntu2.1?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
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            }
          ],
          "type": "ECOSYSTEM"
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      ],
      "versions": [
        "3.3.7-1ubuntu2",
        "3.3.8-2ubuntu1",
        "3.3.8-2ubuntu2",
        "3.3.8-2ubuntu2.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "jruby",
            "binary_version": "9.4.8.0+ds-3ubuntu1"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "jruby",
        "purl": "pkg:deb/ubuntu/jruby@9.4.8.0+ds-3ubuntu1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
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            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "9.4.8.0+ds-3ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libruby3.3",
            "binary_version": "3.3.8-2ubuntu3.1"
          },
          {
            "binary_name": "ruby3.3",
            "binary_version": "3.3.8-2ubuntu3.1"
          }
        ],
        "priority_reason": "Only a memory consumption issue when connecting to untrusted IMAP servers"
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "ruby3.3",
        "purl": "pkg:deb/ubuntu/ruby3.3@3.3.8-2ubuntu3.1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.3.8-2ubuntu2",
        "3.3.8-2ubuntu3",
        "3.3.8-2ubuntu3.1"
      ]
    }
  ],
  "aliases": [],
  "details": "Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5, there is a possibility for denial of service by memory exhaustion when net-imap reads server responses. At any time while the client is connected, a malicious server can send can send a \"literal\" byte count, which is automatically read by the client\u0027s receiver thread. The response reader immediately allocates memory for the number of bytes indicated by the server response. This should not be an issue when securely connecting to trusted IMAP servers that are well-behaved. It can affect insecure connections and buggy, untrusted, or compromised servers (for example, connecting to a user supplied hostname). This issue has been patched in versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5.",
  "id": "UBUNTU-CVE-2025-43857",
  "modified": "2026-07-06T14:07:26Z",
  "published": "2025-04-28T16:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-43857"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-43857"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/ruby/net-imap/security/advisories/GHSA-j3g3-5qv5-52mj"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "low",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-43857"
  ]
}



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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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