Critical Remote Code Execution Vulnerability in Dropbear SSH Server
Summary
ALPINE-CVE-2017-9078: The server in Dropbear before 2017.75 might allow post-authentication root remote code execution because of a double free in cleanup of TCP listeners when the -a option is enabled. Affects dropbear versions < 2017.75-r0. Fixed in 2017.75-r0. How to fix ↓
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Background
Dropbear is a lightweight SSH server and client designed for resource-limited environments. It is widely used in embedded systems and provides secure shell access for remote management. The package is known for its small footprint and efficiency, making it a popular choice for various applications. However, it has been identified to have a critical vulnerability that could allow unauthorized access and control.
Vulnerability Detail
The vulnerability in Dropbear, identified as CVE-2017-9078, arises from a double free error in the cleanup of TCP listeners when the -a option is enabled. This flaw can be exploited post-authentication, allowing an attacker to execute arbitrary code with root privileges remotely. The implications of this vulnerability are severe, as it could lead to complete system compromise, data breaches, and unauthorized access to sensitive information.
How To Fix
Minimum fixed version
2017.75-r0
This is the first release that contains the fix.
sudo apk add --upgrade dropbearTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider disabling the -a option in Dropbear's configuration to mitigate the risk of exploitation until the package can be updated.
Conclusion
The CVE-2017-9078 vulnerability in Dropbear poses a significant risk due to its potential for remote code execution. It is crucial for users to update to the patched version to safeguard their systems. Utilizing tools like Vulert can help monitor and alert for such vulnerabilities in real-time.
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FAQ
CVE-2017-9078 is a vulnerability in Dropbear that allows post-authentication remote code execution due to a double free error.
You can check if your application is affected by using the Vulert playground at Vulert Scanner, which allows you to monitor for open-source vulnerabilities without requiring sign-up.
The risks include unauthorized remote access, potential data breaches, and complete system compromise.
Yes, the patched version of Dropbear is 2017.75-r0. Updating to this version will resolve the vulnerability.
If immediate updating is not possible, disable the -a option in the configuration as a temporary workaround to reduce the risk.
References
Related vulnerabilities
Recent vulnerabilities recorded for dropbear.
