GSD-2021-21404

Vulnerability from gsd - Updated: 2023-12-13 01:23
Details
Syncthing is a continuous file synchronization program. In Syncthing before version 1.15.0, the relay server `strelaysrv` can be caused to crash and exit by sending a relay message with a negative length field. Similarly, Syncthing itself can crash for the same reason if given a malformed message from a malicious relay server when attempting to join the relay. Relay joins are essentially random (from a subset of low latency relays) and Syncthing will by default restart when crashing, at which point it's likely to pick another non-malicious relay. This flaw is fixed in version 1.15.0.
Aliases
Aliases
CVE-2021-21404
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{
  "GSD": {
    "alias": "CVE-2021-21404",
    "description": "Syncthing is a continuous file synchronization program. In Syncthing before version 1.15.0, the relay server `strelaysrv` can be caused to crash and exit by sending a relay message with a negative length field. Similarly, Syncthing itself can crash for the same reason if given a malformed message from a malicious relay server when attempting to join the relay. Relay joins are essentially random (from a subset of low latency relays) and Syncthing will by default restart when crashing, at which point it\u0027s likely to pick another non-malicious relay. This flaw is fixed in version 1.15.0.",
    "id": "GSD-2021-21404",
    "references": [
      "https://www.suse.com/security/cve/CVE-2021-21404.html",
      "https://security.archlinux.org/CVE-2021-21404"
    ]
  },
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "aliases": [
        "CVE-2021-21404"
      ],
      "details": "Syncthing is a continuous file synchronization program. In Syncthing before version 1.15.0, the relay server `strelaysrv` can be caused to crash and exit by sending a relay message with a negative length field. Similarly, Syncthing itself can crash for the same reason if given a malformed message from a malicious relay server when attempting to join the relay. Relay joins are essentially random (from a subset of low latency relays) and Syncthing will by default restart when crashing, at which point it\u0027s likely to pick another non-malicious relay. This flaw is fixed in version 1.15.0.",
      "id": "GSD-2021-21404",
      "modified": "2023-12-13T01:23:10.994733Z",
      "schema_version": "1.4.0"
    }
  },
  "namespaces": {
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        "ASSIGNER": "security-advisories@github.com",
        "ID": "CVE-2021-21404",
        "STATE": "PUBLIC",
        "TITLE": "Crash due to malformed relay protocol message"
      },
      "affects": {
        "vendor": {
          "vendor_data": [
            {
              "product": {
                "product_data": [
                  {
                    "product_name": "syncthing",
                    "version": {
                      "version_data": [
                        {
                          "version_value": "\u003c 1.15.0"
                        }
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                    }
                  }
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              "vendor_name": "syncthing"
            }
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            "value": "Syncthing is a continuous file synchronization program. In Syncthing before version 1.15.0, the relay server `strelaysrv` can be caused to crash and exit by sending a relay message with a negative length field. Similarly, Syncthing itself can crash for the same reason if given a malformed message from a malicious relay server when attempting to join the relay. Relay joins are essentially random (from a subset of low latency relays) and Syncthing will by default restart when crashing, at which point it\u0027s likely to pick another non-malicious relay. This flaw is fixed in version 1.15.0."
          }
        ]
      },
      "impact": {
        "cvss": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        }
      },
      "problemtype": {
        "problemtype_data": [
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            "description": [
              {
                "lang": "eng",
                "value": "CWE-20 Improper Input Validation"
              }
            ]
          }
        ]
      },
      "references": {
        "reference_data": [
          {
            "name": "https://github.com/syncthing/syncthing/security/advisories/GHSA-x462-89pf-6r5h",
            "refsource": "CONFIRM",
            "url": "https://github.com/syncthing/syncthing/security/advisories/GHSA-x462-89pf-6r5h"
          },
          {
            "name": "https://pkg.go.dev/github.com/syncthing/syncthing",
            "refsource": "MISC",
            "url": "https://pkg.go.dev/github.com/syncthing/syncthing"
          },
          {
            "name": "https://github.com/syncthing/syncthing/commit/fb4fdaf4c0a79c22cad000c42ac1394e3ccb6a97",
            "refsource": "MISC",
            "url": "https://github.com/syncthing/syncthing/commit/fb4fdaf4c0a79c22cad000c42ac1394e3ccb6a97"
          },
          {
            "name": "https://github.com/syncthing/syncthing/releases/tag/v1.15.0",
            "refsource": "MISC",
            "url": "https://github.com/syncthing/syncthing/releases/tag/v1.15.0"
          }
        ]
      },
      "source": {
        "advisory": "GHSA-x462-89pf-6r5h",
        "discovery": "UNKNOWN"
      }
    },
    "gitlab.com": {
      "advisories": [
        {
          "affected_range": "\u003c1.15.0",
          "affected_versions": "All versions before 1.15.0",
          "cvss_v2": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
          "cvss_v3": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "cwe_ids": [
            "CWE-1035",
            "CWE-20",
            "CWE-937"
          ],
          "date": "2021-05-21",
          "description": "Syncthing is a continuous file synchronization program. In Syncthing before version 1.15.0, the relay server `strelaysrv` can be caused to crash and exit by sending a relay message with a negative length field. Similarly, Syncthing itself can crash for the same reason if given a malformed message from a malicious relay server when attempting to join the relay. Relay joins are essentially random (from a subset of low latency relays) and Syncthing will by default restart when crashing, at which point it\u0027s likely to pick another non-malicious relay. This flaw is fixed in version 1.15.0.",
          "fixed_versions": [
            "1.15.0"
          ],
          "identifier": "CVE-2021-21404",
          "identifiers": [
            "GHSA-x462-89pf-6r5h",
            "CVE-2021-21404"
          ],
          "not_impacted": "All versions starting from 1.15.0",
          "package_slug": "go/github.com/syncthing/syncthing",
          "pubdate": "2021-05-21",
          "solution": "Upgrade to version 1.15.0 or above.",
          "title": "Improper Input Validation",
          "urls": [
            "https://github.com/syncthing/syncthing/security/advisories/GHSA-x462-89pf-6r5h",
            "https://nvd.nist.gov/vuln/detail/CVE-2021-21404",
            "https://github.com/syncthing/syncthing/commit/fb4fdaf4c0a79c22cad000c42ac1394e3ccb6a97",
            "https://github.com/syncthing/syncthing/releases/tag/v1.15.0",
            "https://pkg.go.dev/github.com/syncthing/syncthing",
            "https://github.com/advisories/GHSA-x462-89pf-6r5h"
          ],
          "uuid": "3611fe62-5734-446a-bfba-85df4ac45c32"
        }
      ]
    },
    "nvd.nist.gov": {
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        "nodes": [
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            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:a:syncthing:syncthing:*:*:*:*:*:*:*:*",
                "cpe_name": [],
                "versionEndExcluding": "1.15.0",
                "vulnerable": true
              }
            ],
            "operator": "OR"
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          "ID": "CVE-2021-21404"
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        "description": {
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              "value": "Syncthing is a continuous file synchronization program. In Syncthing before version 1.15.0, the relay server `strelaysrv` can be caused to crash and exit by sending a relay message with a negative length field. Similarly, Syncthing itself can crash for the same reason if given a malformed message from a malicious relay server when attempting to join the relay. Relay joins are essentially random (from a subset of low latency relays) and Syncthing will by default restart when crashing, at which point it\u0027s likely to pick another non-malicious relay. This flaw is fixed in version 1.15.0."
            }
          ]
        },
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        "references": {
          "reference_data": [
            {
              "name": "https://github.com/syncthing/syncthing/releases/tag/v1.15.0",
              "refsource": "MISC",
              "tags": [
                "Release Notes",
                "Third Party Advisory"
              ],
              "url": "https://github.com/syncthing/syncthing/releases/tag/v1.15.0"
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              "url": "https://pkg.go.dev/github.com/syncthing/syncthing"
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      },
      "impact": {
        "baseMetricV2": {
          "acInsufInfo": false,
          "cvssV2": {
            "accessComplexity": "LOW",
            "accessVector": "NETWORK",
            "authentication": "NONE",
            "availabilityImpact": "PARTIAL",
            "baseScore": 5.0,
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
            "version": "2.0"
          },
          "exploitabilityScore": 10.0,
          "impactScore": 2.9,
          "obtainAllPrivilege": false,
          "obtainOtherPrivilege": false,
          "obtainUserPrivilege": false,
          "severity": "MEDIUM",
          "userInteractionRequired": false
        },
        "baseMetricV3": {
          "cvssV3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
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          "exploitabilityScore": 3.9,
          "impactScore": 3.6
        }
      },
      "lastModifiedDate": "2021-04-14T18:00Z",
      "publishedDate": "2021-04-06T20:15Z"
    }
  }
}



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