CVE-2021-32635
Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container.
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Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
- Puntuación base: 6.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 1.42%
- Percentil entre todas las CVEs puntuadas: 72
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-20, CWE-923
- NVD-CWE-Other
Referencias
- https://github.com/sylabs/singularity/releases/tag/v3.7.4
- https://github.com/sylabs/singularity/security/advisories/GHSA-5mv9-q7fq-9394
- https://security.gentoo.org/glsa/202107-50
- https://github.com/sylabs/singularity/releases/tag/v3.7.4
- https://github.com/sylabs/singularity/security/advisories/GHSA-5mv9-q7fq-9394
- https://security.gentoo.org/glsa/202107-50
JSON original (NVD)
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"value": "Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys."
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"value": "Singularity es una plataforma de contenedores de código abierto. En las versiones 3.7.2 y 3.7.3, debido al uso incorrecto de una URL por defecto, los comandos de acción de `singularity` (`run`/`shell`/`exec`) que especifican un contenedor utilizando una URI `library://` siempre intentarán recuperar el contenedor desde el punto final remoto por defecto (`cloud.sylabs.io`) en lugar del punto final remoto configurado. Un atacante puede ser capaz de empujar un contenedor malicioso al punto final remoto por defecto con un URI que es idéntico al URI utilizado por una víctima con un punto final remoto no predeterminado, ejecutando así el contenedor malicioso. Sólo se ven afectados los comandos de acción (`run`/`shell`/`exec`) contra URIs `library://`. Otros comandos como `pull` / `push` respetan el endpoint remoto configurado. La vulnerabilidad está parcheada en la versión 3.7.4 de Singularity. Existen dos posibles soluciones: Los usuarios sólo pueden interactuar con el endpoint remoto por defecto, o una instalación puede tener una lista de control de ejecución configurada para restringir la ejecución a contenedores firmados con claves seguras específicas"
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"lastModified": "2026-06-17T03:53:19.233",
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