CVE-2024-40647 in sentry-python
Summary
by MITRE • 07/18/2024
sentry-sdk is the official Python SDK for Sentry.io. A bug in Sentry's Python SDK < 2.8.0 allows the environment variables to be passed to subprocesses despite the `env={}` setting. In Python's `subprocess` calls, all environment variables are passed to subprocesses by default. However, if you specifically do not want them to be passed to subprocesses, you may use `env` argument in `subprocess` calls. Due to the bug in Sentry SDK, with the Stdlib integration enabled (which is enabled by default), this expectation is not fulfilled, and all environment variables are being passed to subprocesses instead. The issue has been patched in pull request #3251 and is included in sentry-sdk==2.8.0. We strongly recommend upgrading to the latest SDK version. However, if it's not possible, and if passing environment variables to child processes poses a security risk for you, you can disable all default integrations.
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Analysis
by VulDB Data Team • 06/07/2025
The vulnerability identified as CVE-2024-40647 affects the sentry-sdk Python package, specifically versions prior to 2.8.0, creating a critical security risk through improper environment variable handling in subprocess execution. This issue stems from the Sentry Python SDK's Stdlib integration, which is enabled by default, causing the SDK to inadvertently override Python's subprocess behavior that should normally prevent environment variable leakage to child processes. The flaw manifests when developers use subprocess calls with explicit `env={}` parameters to isolate child processes from parent environment variables, but the buggy SDK version fails to respect this isolation mechanism, leading to unintended information disclosure.
The technical implementation of this vulnerability involves the interaction between the Sentry SDK's automatic instrumentation and Python's subprocess module behavior. When the Stdlib integration is active, the SDK modifies subprocess execution contexts in a way that bypasses the intended environment variable filtering. This creates a situation where even when developers explicitly set `env={}` in their subprocess calls, all environment variables from the parent process continue to propagate to the child processes. The vulnerability directly relates to CWE-200, which covers "Information Exposure," and CWE-254, addressing "Security Misconfiguration" in software design. The flaw represents a failure in process isolation principles and demonstrates how third-party libraries can compromise security controls implemented by application developers.
From an operational perspective, this vulnerability creates significant risk for applications handling sensitive data or operating in security-sensitive environments. Attackers who can influence environment variables in the parent process can potentially inject malicious values into subprocesses, leading to privilege escalation, data exfiltration, or command injection attacks. The default enablement of the Stdlib integration means that virtually all applications using vulnerable versions of the SDK are exposed to this risk without explicit configuration changes. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, where attackers might exploit the leaked environment variables to execute malicious commands through subprocess calls, and T1552.001 for unsecured credentials, as sensitive environment variables could be inadvertently exposed to unauthorized processes.
The remediation strategy involves upgrading to sentry-sdk version 2.8.0 or later, which includes the fix implemented in pull request #3251 that properly respects the `env` parameter in subprocess calls. Organizations unable to immediately upgrade can mitigate the risk by disabling all default integrations within the SDK, which prevents the problematic Stdlib integration from interfering with subprocess behavior. Security teams should conduct inventory assessments to identify all applications using vulnerable SDK versions and implement monitoring for suspicious subprocess activities that might indicate exploitation attempts. The fix addresses the core architectural issue by ensuring proper isolation between parent and child process environments, maintaining the expected security boundaries that developers rely on when implementing subprocess calls with explicit environment variable handling.