SB2022072808 - Retbleed vulnerabilities in Xen

Description

This security bulletin contains information about 4 secuirty vulnerabilities.

1) Type Confusion (CVE-ID: CVE-2022-23816)

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to a branch type confusion. A local user can force the branch predictor to predict the wrong branch type and gain access to sensitive information.

2) Type Confusion (CVE-ID: CVE-2022-23825)

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to a branch type confusion. A local user can force the branch predictor to predict the wrong branch type and gain access to sensitive information.

3) Processor optimization removal or modification of security-critical code (CVE-ID: CVE-2022-29900)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a mistrained branch predictions for return instructions. A local user can execute arbitrary speculative code under certain microarchitecture-dependent conditions. The vulnerability was dubbed  RETbleed.

4) Processor optimization removal or modification of security-critical code (CVE-ID: CVE-2022-29901)

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to the way non-transparent sharing of branch predictor targets between contexts. A local user can exploit the vulnerability to gain access to sensitive information.

Remediation

Install update from vendor's website.

References

• https://xenbits.xen.org/xsa/advisory-407.html