(0Day) Microsoft Exchange ChainedSerializationBinder Deserialization of Untrusted Data Remote Code Execution Vulnerability
As we continue to enhance the security of our cloud, we are going to address the problem of email sent to Exchange Online from unsupported and unpatched Exchange servers. There are many risks associated with running unsupported or unpatched software, but by far the biggest risk is security. Once a version of Exchange Server is no longer supported, it no longer receives security updates; thus, any vulnerabilities discovered after support has ended don’t get fixed. There are similar risks associated with running software that is not patched for known vulnerabilities. Once a security update is released, malicious actors will reverse-engineer the update to get a better understanding of how to exploit the vulnerability on unpatched servers.
The charges were part of an intensifying effort by federal law enforcement agencies, in conjunction with European partners, to combat international cryptocurrency schemes and illegal transactions.
Thousands of small to medium size businesses are suffering as Rackspace have suffered a security incident on their Hosted Exchange service.
Yesterday, 2nd December 2022, Rackspace announced an outage to their Hosted Exchange Server:
Hi, this is a long-time-pending article. We could have published this article earlier (the original bug was reported to MSRC in June 2021 with a 90-days Public Disclosure Policy). However, during communications with MSRC, they explained that since this is an architectural design issue, lots of code changes and testings are expected and required, so they hope to resolve this problem with a one-time CU (Cumulative Update) instead of the regular Patch Tuesday. We understand their situation and agree to extend the deadline.
Circa the beginning of August 2022, while doing security monitoring & incident response services, GTSC SOC team discovered that a critical infrastructure was being attacked, specifically to their Microsoft Exchange application. During the investigation, GTSC Blue Team experts determined that the attack utilized an unpublished Exchange security vulnerability, i.e., a 0-day vulnerability, thus immediately came up with a temporary containment plan.