Into the symmetry

tl;dr Firefox and Java suffered from a moderate vulnerability affecting the elliptic curve point addition algorithm that uses mixed Jacobian-affine coordinates where it can yield a result POINT_AT_INFINITY when it should not. Introduction Few months ago I was working on a vulnerability affecting the internet standard JWE (slides here ) and I got a stroke of luck . Yuppieeee  Basically I was constructing the malicious JWEs needed for the Demo Attack . When something weird happened :S You can try and share with me the surprise I had, the gist is here If you try to execute this class with Java 1.7 you basically have Exception in thread "main" java.lang.IllegalStateException     at sun.security.ec.ECDHKeyAgreement.deriveKey(Native Method)     at sun.security.ec.ECDHKeyAgreement.engineGenerateSecret(ECDHKeyAgreement.java:130)     at javax.crypto.KeyAgreement.generateSecret(KeyAgreement.java:586)     at orig...

Disclaimer Questo blog post e' scritto da evariste.gal0is ed Antonio Sanso . Entrambi gli autori non hanno nessuna affiliazione politica ed il post ha l'unico scopo di fornire un'analisi tecnica di parte dei dump relativa alle password. Riassunto delle puntate precedenti In data 2 agosto 2017 uno dei coautori di questo blog post  ( evariste.gal0is ) ha segnalato Il sito Rousseau del M5S è vulnerabile, voti e dati personali degli iscritti sono tutti a rischio #Hack5Stelle https://t.co/7KPcFsXFhe — evariste.gal0is (@evaristegal0is) August 2, 2017 una severa vulnerabilita' (del tipo SQL injection ) che affligeva la piattaforma del Movimento Cinque Stelle chiamata Rousseau : https://rousseau.movimento5stelle.it/ . La sua segnalazione riceve una notevole copertura mediatica e minacce di querela da parte del  Movimento Cinque Stelle * (cosa che spinge  evariste.gal0is a prendere temporaneamente una pausa). Nel frattempo un black hat hacker che si fa chiama...

tl;dr This short blog post serves to me to recollect some of the thing I have been learning ( climbing ) about Elliptic Curves Cryptography (ECC from now on) during the last months/years, so please take it with a grain of salt since it might contains some erroneous beliefs. '80 - Introduction Giambattista Vico   was an Italian political philosopher and rhetorician, historian and jurist, of the Age of Enlightenment famous (also) for the concept of historical courses and resorts. This can be resumed with: "some events are repeated in the same way even after a long time; and this is not by chance" . Well it seems that this might also applies to ECC so he maybe he was right :) Elliptic Curve made its first appearance in cryptography with Lenstra in 1984 (eventually published in 1987). Curiously enough he introduced them not while trying to come up with a new crypto system but he employed EC in order to factor integers (a side note, there is a really beauti...

Yesterday while reading my Twitter stream I found this interesting article about  downloading GitHub SSO bypass codes . Same as Yasin Soliman I was invited to a Github pre-release of the organisation SAML single sign-on (SSO) private program. And same as him I found an issue in the same endpoint. So I thought to write a quick blog post about it. Github already published a tl;dr about this,  I will try to fill the blanks here. As mentioned by Yasin, Github offers an endpoint where privileged users can recover bypass codes. These recovery codes were accessible for download as plaintext and had the content-type as text/plain , something like: What immediately caught my attention was that the format of the code forms (with some exceptions) a valid JavaScript file with lines in the format of XXXXX-XXXXX , ten hex digits separated by a hyphen. This is interpreted in JavaScript as the subtraction of two variables! This remember an old blog post of mine ...

We all know about this massive Google Doc Phishing Attack that hit about 1 million accounts right? Image from https://arstechnica.com/security/2017/05/dont-trust-oauth-why-the-google-docs-worm-was-so-convincing/ Well this really "sophisticated attack" (really??) was based on a really spread Internet procol named OAuth . It also turns out that during the early stage of the standardization someone reported this very own attack vector but as often happens he was ignored.  Back in 2015 I also reported another "hidden feature"  of OAuth that turns an OAuth server into an open redirector that makes phishing a piece of cake. Yesterday I was twitting about this and today I decided to imitate Eugene Pupov (lol) and work on my master thesis project. So this is the resulting mail. Have fun: Fret not, go ahead and click and you will be redirected to:   that is not a Github page but is rather controlled by me. Well that's all folks...

Note this is going to be a quick post. This year, at Enigma 2017 Conference , Facebook introduced a way to move Account Recovery beyond Email and the "Secret" Question . After the presentation the moved operationally and presented the first integration partner : Github . These days I have seen a lot of press around this and both Facebook and Github open sourced their implementation and s pecification (also presented at F8 ). Well it turned out that Facebook side was susceptible to Cross Site Request Forgery. Really simple explanation: The attacker start the integration with Github and stop the flow at the right moment.  The create an attacker page as https://github.com/asanso/asanso.github.io/blob/master/facebook/test_fb.html <html> <img src="https://www.facebook.com/recovery/delegated/save/?fr=OkpK%2FnF9oZk%3D& relay_token=AfFdhnFYiPWXlcS17dG19Tz4sJT%2B%2FzBorBbDwEKgNMvxUHRIqMAnmmEGrGZlMheUfJdNHv40xyraKOfj64fR7ZgZ8HNNmincyRiHdu6Nju...

tl;dr   Facebook Groups offers the option to upload files directly from the Dropbox account. This integration is done using the OAuth 2.0 protocol and suffered from a variant of the classic OAuth CSRF (defined by Egor Homakov as the the Most Common OAuth2 Vulnerability ),  see video below: Introduction  Facebook Groups offers the option to upload files directly from the Dropbox account: This will allow to surf via browser the Dropbox account  and post a specific file to the group.  This integration is done using a variant of the OAuth 2.0 protocol seen in this blog many many times . But once more, OAuth is an access delegation protocol standardized under the IETF umbrella . A typical OAuth flow would look like: From “OAuth 2 In Action” by Justin Richer and Antonio Sanso, Copyrights 2017 Usually the client initiates the OAuth flow in the following way: From “OAuth 2 In Action” by Justin Richer and Antonio Sa...