← volver
CVE-2021-41272

SHL, SHR, and SAR operations trigger native exception at key values in besu

CVSS 7.5 HIGHEPSS 1.4%CWE-681
En resumen

Besu, un cliente Ethereum, falla al procesar ciertas operaciones de desplazamiento (SHL, SHR, SAR) con valores grandes de bits en contratos inteligentes. Esto causa que el cliente rechace transacciones válidas y puede dividir la red en versiones incompatibles.

Detalle técnico

Un defecto de coerción de enteros con signo en Besu versiones 21.10.0+ causa excepciones nativas en operaciones SHL, SHR y SAR cuando los valores de desplazamiento representan enteros con signo de 32 bits negativos (~2 mil millones a 4 mil millones de bits). La vulnerabilidad afecta la validación de transacciones y aceptación de bloques, pudiendo causar bifurcaciones de red o fallos de consenso según la distribución de nodos vulnerables versus parcheados.

Resumen generado y traducido por IA a partir de la descripción oficial.
Besu is an Ethereum client written in Java. Starting in version 21.10.0, changes in the implementation of the SHL, SHR, and SAR operations resulted in the introduction of a signed type coercion error in values that represent negative values for 32 bit signed integers. Smart contracts that ask for shifts between approximately 2 billion and 4 billion bits (nonsensical but valid values for the operation) will fail to execute and hence fail to validate. In networks where vulnerable versions are mining with other clients or non-vulnerable versions this will result in a fork and the relevant transactions will not be included in the fork. In networks where vulnerable versions are not mining (such as Rinkeby) no fork will result and the validator nodes will stop accepting blocks. In networks where only vulnerable versions are mining the relevant transaction will not be included in any blocks. When the network adds a non-vulnerable version the network will act as in the first case. Besu 21.10.2 contains a patch for this issue. Besu 21.7.4 is not vulnerable and clients can roll back to that version. There is a workaround available: Once a transaction with the relevant shift operations is included in the canonical chain, the only remediation is to make sure all nodes are on non-vulnerable versions.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Productos afectados
hyperledger · besu

¿Quieres saber si tu infraestructura está expuesta a esto?

Hablar con TrueHacking →