Full Disclosure mailing list archives
Re: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction
From: Bipin Gautam <bipin.gautam () gmail com>
Date: Tue, 1 Apr 2014 20:04:13 +0545
Hi, the POC is about "anyone being able to access anyone's facebook profile picture in full resolution" + regardless of the ACL set to their facebook profile picture (say; even when your profile picture permission of your facebook is set as... viewable to "only me" or "friends" ) ...anyone can see your full resolution profile picture even without logging on to facebook with the following method! (Assumption: maybe if you (your ISP?) are using CDN and someone in your ISP / region have already viewed the profile picture and as it is already fetched locally / cached in local CDN so, other party can access it? Does CND have IP restriction for a region / ISP ? ) Try... it works for me, Make sense ? On 4/1/14, Philip Whitehouse <philip () whiuk com> wrote:
This is not a vulnerability. The image path is not predictable. Sharing the URL is by itself giving permission for the other party to see it. Even if it were possible to restrict access it could be circumvented by downloading it and emailing the file instead of the URL Philip Whitehouse ----- Reply message ----- From: "Bipin Gautam" <bipin.gautam () gmail com> To: "fulldisclosure" <fulldisclosure () seclists org> Subject: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction Date: Tue, Apr 1, 2014 10:59 Hi List, I felt like writing / pointing this minor issue, as it as its "Facebook" ... This issue is due to the way facebook pictures are stored in CDN without authentication mechanism, during accessing it. (which would be way technically complicated to implement it) Also, it is a Facebook feature that... if you have full path of an image, you can pass it to anyone over the internet which they can access it directly (and the facebook user should not have unrealistic expectation to privacy. Hence, if someone can access an image they can save/email it to others, anyway.) POC: ( Please TEST it in a real profile, real world example and it should work. I obviously changed the URL, POC below, to gibberish "6549_16544614736_444444875_n.jpg" ) STEPS: You could try this by : - changing your own facebook profile picture viewable to "only me", then bookmark your own Facebook profile and logout and clear cache. - or then try different browser with your own profile from bookmark, without logging in to facebook! - or pass your FB profile to a friend, with the following instruction. ___ - then, in your browser, "Right click the Facebook profile image" that you want to access in full resolution (that have ACL as access to "only me" or "friends" ) > click "Copy image location" > paste it in notepad sample url you will get (this link below is broken) :[1] https://fbcdn-profile-a.akamaihd.net/hprofile-ak-frc3/t1.0-1/c0.18.160.160/p160x160/6549_16544614736_444444875_n.jpg to remove from [1]: "/c0.18.160.160/p160x160" (part; in other cases, the url structure may be different, you just have to find and remove this middle part...) final modified url from above, which you can access the profile picture in full resolution via your browser : https://fbcdn-profile-a.akamaihd.net/hprofile-ak-frc3/t1.0-1/6549_16544614736_444444875_n.jpg Respectfully, -bipin
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Current thread:
- Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction Bipin Gautam (Apr 01)
- Re: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction Mario Vilas (Apr 01)
- Re: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction Źmicier Januszkiewicz (Apr 02)
- Re: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction illwill (Apr 03)
- <Possible follow-ups>
- Re: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction Philip Whitehouse (Apr 01)
- Re: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction Bipin Gautam (Apr 01)
- Re: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction Philip Whitehouse (Apr 01)
- Re: Access anyone's Facebook "profile picture" in full resolution regardless of the ACL restriction Sven 'Darkman' Michels (Apr 01)