Determine security ramifications to protect personal data and information
111 Discussions

Chips & Salsa Episode 21: July 2022 Security Advisories - Retbleed

0 0 11.6K

Hi everyone,

Today Intel released two security advisories addressing 2 medium severity vulnerabilities reported by academic researchers from ETH Zurich who have labeled their side-channel attack as “Retbleed” due to finding  a method to potentially bypass a commonly used mitigation technique known as retpoline. 

Intel has worked with the Linux community and VMM vendors to provide customers with software mitigation guidance which should be available on or around today's public disclosure date. Note that Windows systems are not affected given that these systems use Indirect Branch Restricted Speculation (IBRS) by default which is is also the mitigation being made available to Linux users. Intel is not aware of this issue being exploited outside of a controlled lab environment.

Intel will release a software security guidance - article titled Return Stack Buffer Underflow RSBU informing software vendors how to mitigate these issues. Customers should review the software security guidance to understand which Intel processors may be affected and available options to enable/disable these mitigations.

Note that in the Intel technical paper titled Retpoline: A Branch Target Injection Mitigation, originally published on 1/3/2018, the issue found by researchers, is called out as a potential risk which we refer to as ‘Empty RSB’. 

For these and other Intel security advisories, please visit the Intel Product Security Center.

About the Chips & Salsa video series:

Chips and Salsa is a regular video series with hosts Jerry Bryant and Christopher “CRob” Robinson.  The videos cover such topics as vulnerability disclosures, security incident response, security assurance practices, security technologies with thought-provoking interviews with subject matter experts from Intel and across the security technology spectrum.


Jerry Bryant
Sr. Director of Security Communications and Incident Response
Intel Product Assurance and Security

About the Author
Intel Product Assurance and Security (IPAS) is designed to serve as a security center of excellence – a sort of mission control – that looks across all of Intel. Beyond addressing the security issues of today, we are looking longer-term at the evolving threat landscape and continuously improving product security in the years ahead.