CVE-2017-7528

Vulnerability

CVE-2017-7528 is a CRLF injection vulnerability in Ansible Tower as shipped with Red Hat CloudForms Management Engine 5. The vulnerability resides in the handling of the X-Forwarded-For HTTP header. By injecting CRLF sequences into this header, an attacker can manipulate the server's internal callback mechanism to deploy other systems. This affects Red Hat CloudForms Management Engine 5 [1].

Exploitation

An attacker with network access to an internal network that can reach the vulnerable Ansible Tower instance can craft a malicious X-Forwarded-For header containing CRLF sequences. The attacker does not require authentication but must be able to send HTTP requests to the Tower's callback endpoint. The injection causes the server to misinterpret the header content, potentially allowing the attacker to trigger deployment of new systems that the Tower manages [1].

Impact

Successful exploitation allows an attacker to deploy other systems within the environment, bypassing intended access controls. This can lead to unauthorized provisioning or modification of infrastructure, potentially resulting in information disclosure or further compromise of the managed systems [1].

Mitigation

Red Hat has released a fix for this vulnerability as part of a security update. The fix was included in Red Hat CloudForms Management Engine 5's advisory (RHSA-2017:2528) published on August 22, 2018. Users should update to the latest patched version of Ansible Tower and CloudForms to mitigate this issue [1].