Winter Soldier's powers and abilities
Thanks to Nick Fury and his Infinity Formula, Bucky's longevity and his aging process has been enhanced. But without repeat exposure he will begin to age normally overtime.
It was used to replace Bucky's missing arm.
Has some degree of superhuman strength in his bionic arm.
Enhanced Reaction Time
His arm's reaction time is greater than that of any Olympic athlete who has and will ever compete.
The arm houses different sensors which allow him to pass through security such as metal detectors without setting them off. It can also shield other metallic objects from detection such as firearms and knives.
He can apparently either control his bionic arm even if it has been removed from his body (possibly by cybernetic implants), or his arm can be programmed to perform certain actions on its own while removed from his body.
He can discharge bolts of electrical energy from his arm's palm.
He can discharge an EMP rendering electronic devices useless. He failed to use it on a prepared Iron Man.
Olympic to peak human strength and some level of superhuman strength in bionic arm.
Master Martial Artist
Barnes is a dangerously skilled martial artist and hand-to-hand combatant. He received training from World War Two hand-to-hand combat luminaries William Essart Fairbairn and Colonel Rex Applegate as well as Captain America (Steve Rogers) in multiple martial arts, and acrobatics as a teenager during WWII and was trained in more of them while being molded into an assassin by the Soviet Union. He has single-handedly beaten Crossbones, a squad of SHIELD agents, Wolverine and the Black Widow, defeated a regiment of Hydra agents alongside the Young Avengers, in combat and fought Captain America (Steve Rogers) and Iron Man to a standstill.
He is an extremely accurate marksman. Skilled in sharpshooting and knife throwing.
Skilled Shield Fighter
Barnes is becoming rapidly proficient with his former partner's shield. He is able to throw it with near perfect aim striking multiple targets in a single throw and achieving a boomerang-like return after throwing it at single person or object.
He is an Olympic level athlete and acrobat capable of many difficult acrobatic feats.
Peak Human Conditioning
Has shown Olympic to possible near peak human level strength, agility, endurance, dexterity, etc.
Barnes is a very gifted scout and adept at stealth and concealment.
He is fluent in English, Russian, German, Japanese, and a little French. He might be able to speak other languages.
He is an expert in the field of espionage thanks largely to World War Two hand-to-hand combat luminaries William Essart Fairbairn and Colonel Rex Applegate, his former partner, Steve Rogers, the United States military, British SAS regiment, and the Russian Government. He is skilled in stealth, demolitions, survival, deducing other persons ways of thinking and other fields.
Barnes is an adept of his generation as Matthew Murdock and Elektra Natchios is of theirs, possibly the most lethal assassin in the marvel universe rivaling others such as Bullseye or Elektra. During an operation on the Russian Front with the Invaders, Barnes has from concealment thrown a 60 centimeters-long knife to penetrate the winter uniform outer garment of a German soldier with such accuracy as to pierce his heart in high arctic winds several meters. Barnes has mastered and implemented several methods to silently eliminate sentries with bladed weapons, garrotes or his bare hands, making him as lethal in his own way as his former Invader teammates, the Torches, Union Jack or Namor. He is a master at stealth and tracking and is very intelligent. He was able to render Wolverine's superhumanly acute senses such as smell completely useless by luring him to an abandoned warehouse that was completely soaked on the inside with oil and even soaking himself to make it so that Wolverine could not detect him. Barnes has made a habit out of constantly studying his surroundings and depicting what he can and cannot do in whatever situation he should fall in much like his former partner, Captain America before his death. During Barnes' visit to the Captain America exhibit that had been made to honor him after his death, he was constantly detecting potential ways to sneak in and out of the museum and the room without being detected and only taking out a small number of security to do so. The Black Widow stated to Tony Stark that he was one of the most dangerous men she knew.