CVE-2020-11934

It was discovered that snapctl user-open allowed altering the $XDG_DATA_DIRS environment variable when calling the system xdg-open. OpenURL() in usersession/userd/launcher.go would alter $XDG_DATA_DIRS to append a path to a directory controlled by the calling snap. A malicious snap could exploit this to bypass intended access restrictions to control how the host system xdg-open script opens the URL and, for example, execute a script shipped with the snap without confinement. This issue did not affect Ubuntu Core systems. Fixed in snapd versions 2.45.1ubuntu0.2, 2.45.1+18.04.2 and 2.45.1+20.04.2.

CVSS v3 5.9 MEDIUM
CVSS v2.0 1.9 LOW

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.5 / Impact : 4.0

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

1.9^/10

CVSS v2.0 : LOW

Vector : AV:L/AC:M/Au:N/C:N/I:P/A:N

Exploitability : 3.4 / Impact : 2.9

Access Vector LOCAL

Access Complexity MEDIUM

Authentication NONE

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
https://launchpad.net/bugs/1880085	Third Party Advisory
https://ubuntu.com/USN-4424-1	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:canonical:ubuntu_linux:16.04::::lts:::
	cpe:2.3:o:canonical:ubuntu_linux:18.04::::lts:::
	cpe:2.3:o:canonical:ubuntu_linux:19.10:::::::*
	cpe:2.3:o:canonical:ubuntu_linux:20.04::::lts:::

History

No history.

Information

Published : 2020-07-29 17:15

Updated : 2023-12-10 13:27

NVD link : CVE-2020-11934

Mitre link : CVE-2020-11934

CVE.ORG link : CVE-2020-11934

JSON object : View

Products Affected

canonical

ubuntu_linux

CWE

CWE-668

Exposure of Resource to Wrong Sphere

{"id": "CVE-2020-11934", "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 1.9, "accessVector": "LOCAL", "vectorString": "AV:L/AC:M/Au:N/C:N/I:P/A:N", "authentication": "NONE", "integrityImpact": "PARTIAL", "accessComplexity": "MEDIUM", "availabilityImpact": "NONE", "confidentialityImpact": "NONE"}, "acInsufInfo": false, "impactScore": 2.9, "baseSeverity": "LOW", "obtainAllPrivilege": false, "exploitabilityScore": 3.4, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": true}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 4.0, "exploitabilityScore": 1.5}, {"type": "Secondary", "source": "security@ubuntu.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 4.0, "exploitabilityScore": 1.5}]}, "published": "2020-07-29T17:15:12.967", "references": [{"url": "https://launchpad.net/bugs/1880085", "tags": ["Third Party Advisory"], "source": "security@ubuntu.com"}, {"url": "https://ubuntu.com/USN-4424-1", "tags": ["Vendor Advisory"], "source": "security@ubuntu.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-668"}]}], "descriptions": [{"lang": "en", "value": "It was discovered that snapctl user-open allowed altering the $XDG_DATA_DIRS environment variable when calling the system xdg-open. OpenURL() in usersession/userd/launcher.go would alter $XDG_DATA_DIRS to append a path to a directory controlled by the calling snap. A malicious snap could exploit this to bypass intended access restrictions to control how the host system xdg-open script opens the URL and, for example, execute a script shipped with the snap without confinement. This issue did not affect Ubuntu Core systems. Fixed in snapd versions 2.45.1ubuntu0.2, 2.45.1+18.04.2 and 2.45.1+20.04.2."}, {"lang": "es", "value": "Se detect\u00f3 que snapctl user-open permit\u00eda alterar la variable de entorno $XDG_DATA_DIRS cuando se llama al sistema xdg-open. La funci\u00f3n OpenURL() en el archivo usersession/userd/launcher.go alterar\u00eda $XDG_DATA_DIRS para agregar una ruta a un directorio controlado por el complemento de llamada. Un complemento malicioso podr\u00eda explotar esto para omitir las restricciones de acceso previstas para controlar c\u00f3mo el script xdg-open del sistema host abre la URL y, por ejemplo, ejecuta un script enviado con el complemento sin confinamiento. Este problema no afect\u00f3 a los sistemas Ubuntu Core. Corregido en las versiones snapd 2.45.1ubuntu0.2, 2.45.1+18.04.2 y 2.45.1+20.04.2"}], "lastModified": "2020-08-05T18:46:07.417", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*", "vulnerable": true, "matchCriteriaId": "F7016A2A-8365-4F1A-89A2-7A19F2BCAE5B"}, {"criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*", "vulnerable": true, "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D"}, {"criteria": "cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A31C8344-3E02-4EB8-8BD8-4C84B7959624"}, {"criteria": "cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*", "vulnerable": true, "matchCriteriaId": "902B8056-9E37-443B-8905-8AA93E2447FB"}], "operator": "OR"}]}], "sourceIdentifier": "security@ubuntu.com"}