This discussion focuses on addressing various CPU vulnerabilities including Spectre and RETBleed, as identified in the system logs on a machine running OS Version 8.7 and Kernel Version 4.18.0-477.13.1.el88.x8664.
The log entries indicate exposure to multiple vulnerabilities such as Spectre V1, Spectre V2, RETBleed, Speculative Store Bypass, TAA (TSX Asynchronous Abort), and MMIO Stale Data. Mitigations like Retpolines and usercopy/swapgs barriers are in place for Spectre V1 and V2, but the log specifically highlights a significant concern with RETBleed, stating that the current Spectre v2 mitigations do not adequately protect against RETBleed attacks, leaving the possibility of data leaks.
To mitigate these risks on the specified OS and Kernel version, it is crucial to apply the latest security patches and updates available for the OS. This includes updating to the most recent kernel that may contain enhanced mitigations against these threats. Additionally, checking for and applying CPU microcode updates from the hardware manufacturer is necessary, especially since the logs mentioned vulnerabilities like TAA and MMIO Stale Data stemming from insufficient microcode updates.
Can help how we can prevent this vulnerable. Below error.
dmesg | grep -i ‘spectre|retbleed|vulnerab’
[ 0.068005] Spectre V1 : Mitigation: usercopy/swapgs barriers and __user pointer sanitization
[ 0.069002] Spectre V2 : Mitigation: Retpolines
[ 0.070000] Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch
[ 0.071000] Spectre V2 : Spectre v2 / SpectreRSB : Filling RSB on VMEXIT
[ 0.072000] RETBleed: WARNING: Spectre v2 mitigation leaves CPU vulnerable to RETBleed attacks, data leaks possible!
[ 0.073000] RETBleed: Vulnerable
[ 0.074000] Speculative Store Bypass: Vulnerable
[ 0.075007] TAA: Vulnerable: Clear CPU buffers attempted, no microcode
[ 0.076000] MMIO Stale Data: Vulnerable: Clear CPU buffers attempted, no microcode
If we upgrade OS version is 8.10 it fix the issue.