A buffer overflow vulnerability has been discovered in OpenSSL's X.509 certificate verification process, specifically in the name constraint checking. Attackers can craft a malicious email address to overflow four attacker-controlled bytes on the stack, possibly causing denial of service or even remote code execution. This vulnerability has been identified as CVE-2022-3602 with a HIGH rating. Users are advised to update OpenSSL to the 3..7 version to fix the issue.
Body
A recent critical vulnerability has been discovered in the OpenSSL library, which is widely used for the implementation of TLS and SSL protocols. This vulnerability, identified as CVE-2022-3602, affects the X.509 certificate verification process and is related to the name constraint checking. In this vulnerability, a buffer overrun can be triggered, which may result in a crash or potentially compromise the system for remote code execution.
The vulnerability was initially assessed as CRITICAL, but after further analysis and considering the mitigating factors, its severity has been downgraded to HIGH. Nevertheless, users are strongly advised to update their OpenSSL installations to version 3..7 in order to mitigate the risk, as the issue affects previous 3..x releases.
This buffer overflow occurs after the certificate chain signature verification and requires either a maliciously signed certificate or an application that proceeds with certificate verification even after failing to construct a trusted issuer path. In simpler terms, the attacker would need to craft a malicious email address that overflows four bytes on the stack, exploiting this vulnerability.
To give an understanding of what an attacker may use to trigger the buffer overflow, here's a sample code snippet:
Email = "attacker@example.org" * 256
Many platforms implement stack overflow protection mechanisms to minimize the risk of remote code execution. Moreover, stack layout differences across platforms and compilers may also contribute to reducing the potential impact. However, it is crucial to update OpenSSL to the latest version in order to minimize the associated risks.
In the context of TLS, the vulnerability can be exploited by clients connecting to a malicious server, or in cases where a TLS server requests client authentication and a malicious client connects. The fix for this issue has been implemented in OpenSSL 3..7, and all affected 3..x versions should be updated.
Original references
1. OpenSSL Advisory: [OpenSSL Security Advisory [24th June 2022]](https://www.openssl.org/news/secadv/20210624.txt)
2. CVE Details: CVE-2022-3602 Detail
Recommendations
Users and system administrators are encouraged to update their OpenSSL installations to version 3..7 as soon as possible in order to protect their systems and applications from the potential consequences of this buffer overflow vulnerability. Upgrading OpenSSL will reduce the risks associated with denial of service attacks and potential remote code execution that are associated with CVE-2022-3602.
Timeline
Published on: 11/01/2022 18:15:00 UTC
Last modified on: 11/04/2022 19:49:00 UTC