Authentication Bypass Vulnerability in strongswan
Summary
DSA-3398-1: strongswan - security update. Affects strongswan versions < 4.5.2-1.5+deb7u8. Fixed in 4.5.2-1.5+deb7u8. How to fix ↓
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Background
strongSwan is an IKE/IPsec suite that provides secure communication over the internet. It allows for the establishment of Virtual Private Networks (VPNs) and ensures the confidentiality, integrity, and authenticity of transmitted data. However, a vulnerability has been discovered in the EAP-MSCHAPv2 protocol implementation of the eap-mschapv2 plugin in strongSwan.
Vulnerability Detail
The server implementation of the EAP-MSCHAPv2 protocol in strongSwan is susceptible to an authentication bypass vulnerability. This vulnerability arises due to insufficient validation of the local state. An attacker can exploit this flaw to successfully conclude the authentication process without providing valid credentials. This can lead to unauthorized access and potential security breaches. The attack can be identified by checking the server logs for the following message: 'EAP method EAP_MSCHAPV2 succeeded, no MSK established'.
How To Fix
Minimum fixed version
4.5.2-1.5+deb7u8
This is the first release that contains the fix.
sudo apt-get install --only-upgrade strongswanTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Conclusion
The authentication bypass vulnerability in strongSwan's EAP-MSCHAPv2 protocol implementation can allow attackers to bypass authentication and gain unauthorized access to the server. It is crucial to upgrade the strongswan package to the fixed versions mentioned to mitigate this vulnerability. For further support on vulnerability remediation, contact DevNack.com.
See every vulnerability recorded for strongswan →
FAQ
strongSwan is an IKE/IPsec suite that provides secure communication over the internet. It is commonly used for establishing Virtual Private Networks (VPNs) and ensuring the confidentiality, integrity, and authenticity of transmitted data.
The EAP-MSCHAPv2 protocol is an authentication protocol used in strongSwan for secure communication. It allows clients to authenticate themselves to the server using their credentials.
You can identify if your strongSwan server is affected by checking the server logs for the following message during client authentication: 'EAP method EAP_MSCHAPV2 succeeded, no MSK established'. If this message is present, it indicates a successful authentication bypass attack.
This vulnerability can lead to unauthorized access to the strongSwan server, potentially resulting in security breaches and the compromise of sensitive data transmitted over the network.
To fix this vulnerability, it is recommended to upgrade the strongswan package to the fixed versions provided for each distribution. Refer to the 'how_to_fix' section for the specific versions.
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