Question CrystalDiskinfo says 672 reallocated sector count, what this mean?

CrystalDiskInfo shows yellow on my HDD and says

Reallocated sector count = 672
Current pending sector count = 8
Uncorrectable sector count = 8

SSD
Good 77%

Please tell me what this mean
It means your HDD is having to move data around because it is failing to write it where first scheduled. It means your HDD is more likely to fail. It is NOT a predictor, but it is a warning. AS @USAFRet said you should be backing up any important data and preparing to replace that HDD.
 
Is there anyway to correct this. Is this caused due to dust?
No, and No. A HDD is a sealed unit. Disks fail. That is a normal thing. That model disk drive has been available since 2017 so your disk could easily be 5+ years old. It has 600+ continuous days of use with 4000+ power cycles. Is is just time to prepare to replace it.