back door

• backdoor, back-door

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back door (plural back doors)

1. A subsidiary entrance to a building or house at its rear, normally away from the street.
   • 2023 January 11, Stephen Roberts, “Bradshaw's Britain: castles and cathedrals”, in RAIL, number 974, page 57:

     "Charles II, who was crowned here a little while before, occupied an old house (which is still standing) in New Street [Worcester], from which he escaped by the back door, as the enemy rushed in at the front."

2. A means of access, often secret and unprotected, to something.
   • 2021 November 29, Alan Shearer, “Why Newcastle have to win their next two games to give them hope of staying in the Premier League - Alan Shearer analysis”, in BBC Sport‎:

     Scoring three goals at home should guarantee you three points, but when you go on the attack a little bit more, you leave the back door open. That's not always a good idea with this team.

3. (computer security) A secret means of access to a program or system.
4. (automotive) A rear side door of a car, or at the back of a van.
5. (slang) The anus; (by extension) anal sex.

   Synonym: backgate

   backdoor action

   go up the back door

   • 1998 June 28, Michael Patrick King, “Valley of the Twenty-Something Guys”, in Sex and the City, season 1, episode 4, spoken by Samantha:

     Oh, don't be so judgmental. You could use a little back door.

6. (golf, informal) The rear side of the hole, furthest from the golfer.
   • 2010, Bob Glanville, Golf: The Game of Lessening Failures, page 14:

     Sometimes the ball will curve around and enter from the back-door.

• foredoor
• front door

• back-door bandit
• back-door man
• back-door pilot

back door (not comparable)

1. (US, baseball) The path of a pitch which starts outside and then slides over the plate.

   He has a nasty back door slider.

2. Achieved through indirect means.
3. (poker, of a draw) Requiring consecutive cards on the turn and river to be achieved.

   The flop had the ace of spades, queen of spades, and two of diamonds, and I was holding the king of spades and the three of hearts. I bet big, hoping for a jack and a ten to make my back door straight-draw, or a spade to make my back door flush-draw. But when the turn card was the five of clubs, I had to fold.

• back door slider

back door (third-person singular simple present back doors, present participle back dooring, simple past and past participle back doored)

1. To attempt to accomplish by indirect means, especially when direct means are proscribed.
2. (surfing) To enter a tube by accelerating from behind; to surf into an already formed hollow wave, in contrast to the normal method of slowing to allow a surfable wave to form.
   • 1999, Mark Warren, Mark Warren's Atlas of Australian Surfing, traveller's, →ISBN, page 103:

     If you survive the heavy take-off at 'The Chair' (which is very close to the rocks) you will find you're in 'The Suck-up', which offers either a spectacular barrel or a bonecrunching wipeout, but you might find you have to back door it.

3. (computer security) To add a backdoor (a secret means of access) to a program or system.
   • 2018 February 26, Abhinav Singh, Nipun Jaswal, Monika Agarwal, Daniel Teixeira, Metasploit Penetration Testing Cookbook: Evade antiviruses, bypass firewalls, and exploit complex environments with the most widely used penetration testing framework, 3rd Edition, Packt Publishing Ltd, →ISBN, page 213:

     Now that we have backdoored the notepad.exe binary, we will go back to the Meterpreter session and upload our backdoor: 3. Then, we need to start a listener so we. meterpreter > upload notepad-backdoored.exe [*] uploading […]

   • 2015 April 13, Elisabeth Oswald, Marc Fischlin, Advances in Cryptology – EUROCRYPT 2015: 34th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Sofia, Bulgaria, April 26-30, 2015, Proceedings, Part I, Springer, →ISBN, page 103:

     As an example, the generation algorithm for backdoored Dual EC picks a fixed group element Q, a random exponent d, and outputs as public key the pair P = Qd and Q. The secret key is d. (We use multiplicative notation for simplicity.) […]

   • 2019 July 18, Gilberto Najera-Gutierrez, Juned Ahmed Ansari, Daniel Teixeira, Abhinav Singh, Improving your Penetration Testing Skills: Strengthen your defense against web attacks with Kali Linux and Metasploit, Packt Publishing Ltd, →ISBN, page 453:

     Back in the session, we will rename the httpd.exe file to httpd.exe.backup, upload the backdoored version, and rename it to httpd.exe: msf exploit(handler) > sessions -i 1 [*] Starting interaction with 1... meterpreter > cd […]

• front door

• back door on Wikipedia.Wikipedia
• backdoor (computing) on Wikipedia.Wikipedia
• Jonathon Green (2024) “back-door n.”, in Green’s Dictionary of Slang