cvelist/2021/21xxx/CVE-2021-21261.json

{
    "CVE_data_meta": {
        "ASSIGNER": "security-advisories@github.com",
        "ID": "CVE-2021-21261",
        "STATE": "PUBLIC",
        "TITLE": "Flatpak sandbox escape via spawn portal"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "flatpak",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_value": ">= 0.11.4, < 1.8.5"
                                        },
                                        {
                                            "version_value": ">= 1.9.0, < 1.10.0"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "flatpak"
                }
            ]
        }
    },
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. A bug was discovered in the `flatpak-portal` service that can allow sandboxed applications to execute arbitrary code on the host system (a sandbox escape). This sandbox-escape bug is present in versions from 0.11.4 and before fixed versions 1.8.5 and 1.10.0. The Flatpak portal D-Bus service (`flatpak-portal`, also known by its D-Bus service name `org.freedesktop.portal.Flatpak`) allows apps in a Flatpak sandbox to launch their own subprocesses in a new sandbox instance, either with the same security settings as the caller or with more restrictive security settings. For example, this is used in Flatpak-packaged web browsers such as Chromium to launch subprocesses that will process untrusted web content, and give those subprocesses a more restrictive sandbox than the browser itself. In vulnerable versions, the Flatpak portal service passes caller-specified environment variables to non-sandboxed processes on the host system, and in particular to the `flatpak run` command that is used to launch the new sandbox instance. A malicious or compromised Flatpak app could set environment variables that are trusted by the `flatpak run` command, and use them to execute arbitrary code that is not in a sandbox. As a workaround, this vulnerability can be mitigated by preventing the `flatpak-portal` service from starting, but that mitigation will prevent many Flatpak apps from working correctly. This is fixed in versions 1.8.5 and 1.10.0."
            }
        ]
    },
    "impact": {
        "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N",
            "version": "3.1"
        }
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "name": "https://github.com/flatpak/flatpak/security/advisories/GHSA-4ppf-fxf6-vxg2",
                "refsource": "CONFIRM",
                "url": "https://github.com/flatpak/flatpak/security/advisories/GHSA-4ppf-fxf6-vxg2"
            },
            {
                "name": "https://github.com/flatpak/flatpak/releases/tag/1.8.5",
                "refsource": "MISC",
                "url": "https://github.com/flatpak/flatpak/releases/tag/1.8.5"
            },
            {
                "name": "DSA-4830",
                "refsource": "DEBIAN",
                "url": "https://www.debian.org/security/2021/dsa-4830"
            },
            {
                "name": "https://github.com/flatpak/flatpak/commit/6d1773d2a54dde9b099043f07a2094a4f1c2f486",
                "refsource": "MISC",
                "url": "https://github.com/flatpak/flatpak/commit/6d1773d2a54dde9b099043f07a2094a4f1c2f486"
            },
            {
                "name": "https://github.com/flatpak/flatpak/commit/6e5ae7a109cdfa9735ea7ccbd8cb79f9e8d3ae8b",
                "refsource": "MISC",
                "url": "https://github.com/flatpak/flatpak/commit/6e5ae7a109cdfa9735ea7ccbd8cb79f9e8d3ae8b"
            },
            {
                "name": "https://github.com/flatpak/flatpak/commit/aeb6a7ab0abaac4a8f4ad98b3df476d9de6b8bd4",
                "refsource": "MISC",
                "url": "https://github.com/flatpak/flatpak/commit/aeb6a7ab0abaac4a8f4ad98b3df476d9de6b8bd4"
            },
            {
                "name": "https://github.com/flatpak/flatpak/commit/cc1401043c075268ecc652eac557ef8076b5eaba",
                "refsource": "MISC",
                "url": "https://github.com/flatpak/flatpak/commit/cc1401043c075268ecc652eac557ef8076b5eaba"
            },
            {
                "refsource": "GENTOO",
                "name": "GLSA-202101-21",
                "url": "https://security.gentoo.org/glsa/202101-21"
            }
        ]
    },
    "source": {
        "advisory": "GHSA-4ppf-fxf6-vxg2",
        "discovery": "UNKNOWN"
    }
}