As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#2120, SAN-BOS. ' STRONG DIRTY SOCK ODOR IN FLIGHT DECK ONLY ON DESCENT AT LOW POWER SETTING; REF LOG ITEM 3859910 (REPLACE BOTH CABIN RECIRCULATION FILTERS (DE-CONTAMINATION) ECS DECONTAMINATION PERFORMED. APU FOUND LEAKING. REF MDDR 526553 ON LOG ITEM 3859909 FOR APU DEFERRAL.'