// For flags

CVE-2021-32635

Action Commands (run/shell/exec) Against Library URIs Ignore Configured Remote Endpoint

Severity Score

6.3
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

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

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-05-12 CVE Reserved
  • 2021-05-28 CVE Published
  • 2024-08-03 CVE Updated
  • 2024-10-15 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-20: Improper Input Validation
  • CWE-923: Improper Restriction of Communication Channel to Intended Endpoints
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Sylabs
Search vendor "Sylabs"
 Singularity
Search vendor "Sylabs" for product "Singularity"
 3.7.2
Search vendor "Sylabs" for product "Singularity" and version "3.7.2"
-
Affected
Sylabs
Search vendor "Sylabs"
 Singularity
Search vendor "Sylabs" for product "Singularity"
 3.7.3
Search vendor "Sylabs" for product "Singularity" and version "3.7.3"
-
Affected