diff --git a/Insecure Randomness/README.md b/Insecure Randomness/README.md index 8471b42a7d..b33bac449c 100644 --- a/Insecure Randomness/README.md +++ b/Insecure Randomness/README.md @@ -4,13 +4,17 @@ * [GUID / UUID](#guid--uuid) * [GUID Versions](#guid-versions) - * [Tools](#tools) * [Mongo ObjectId](#mongo-objectid) - * [Tools](#tools) +* [Uniqid](#uniqid) +* [Other](#other) * [References](#references) + ## GUID / UUID +A GUID (Globally Unique Identifier) or UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. They are typically represented as a string of hexadecimal digits, divided into five groups separated by hyphens, such as `550e8400-e29b-41d4-a716-446655440000`. GUIDs/UUIDs are designed to be unique across both space and time, reducing the likelihood of duplication even when generated by different systems or at different times. + + ### GUID Versions Version identification: `xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx` @@ -25,6 +29,7 @@ The four-bit M and the 1- to 3-bit N fields code the format of the UUID itself. | 4 | randomly generated | | 5 | based on a SHA1 hash | + ### Tools * [intruder-io/guidtool](https://github.com/intruder-io/guidtool) - A tool to inspect and attack version 1 GUIDs @@ -40,6 +45,7 @@ The four-bit M and the 1- to 3-bit N fields code the format of the UUID itself. $ guidtool 1b2d78d0-47cf-11ec-8d62-0ff591f2a37c -t '2021-11-17 18:03:17' -p 10000 ``` + ## Mongo ObjectId Mongo ObjectIds are generated in a predictable manner, the 12-byte ObjectId value consists of: @@ -48,6 +54,11 @@ Mongo ObjectIds are generated in a predictable manner, the 12-byte ObjectId valu * **Process ID** (2 bytes): Identifies the process that generated the ObjectId. Typically the process ID of the MongoDB server process, making it predictable for documents created by the same process. * **Counter** (3 bytes): A unique counter value that is incremented for each new ObjectId generated. Initialized to a random value when the process starts, but subsequent values are predictable as they are generated in sequence. +Token example + +* `5ae9b90a2c144b9def01ec37`, `5ae9bac82c144b9def01ec39` + + ### Tools * [andresriancho/mongo-objectid-predict](https://github.com/andresriancho/mongo-objectid-predict) - Predict Mongo ObjectIds @@ -57,8 +68,87 @@ Mongo ObjectIds are generated in a predictable manner, the 12-byte ObjectId valu 5ae9bacf2c144b9def01ec3a 5ae9bada2c144b9def01ec3b ``` +* Python script to recover the `timestamp`, `process` and `counter` + ```py + def MongoDB_ObjectID(timestamp, process, counter): + return "%08x%08x%06x" % ( + timestamp, + process, + counter, + ) + + def reverse_MongoDB_ObjectID(token): + timestamp = int(token[0:8], 16) + process = int(token[8:16], 16) + counter = int(token[16:], 16) + return timestamp, process, counter + + + tokens = ["5ae9b90a2c144b9def01ec37", "5ae9bac82c144b9def01ec39"] + for token in tokens: + (timestamp, process, counter) = reverse_MongoDB_ObjectID(token) + print(f"{token}: {timestamp} - {process} - {counter}") + ``` + + +## Uniqid + +Token derived using `uniqid` are based on timestamp and they can be reversed. + +* [Riamse/python-uniqid](https://github.com/Riamse/python-uniqid/blob/master/uniqid.py) is based on a timestamp +* [php/uniqid](https://github.com/php/php-src/blob/master/ext/standard/uniqid.c) + +Token examples + +* uniqid: `6659cea087cd6`, `6659cea087cea` +* sha256(uniqid): `4b26d474c77daf9a94d82039f4c9b8e555ad505249437c0987f12c1b80de0bf4`, `ae72a4c4cdf77f39d1b0133394c0cb24c33c61c4505a9fe33ab89315d3f5a1e4` + + +### Tools + +```py +import math +import datetime + +def uniqid(timestamp: float) -> str: + sec = math.floor(timestamp) + usec = round(1000000 * (timestamp - sec)) + return "%8x%05x" % (sec, usec) + +def reverse_uniqid(value: str) -> float: + sec = int(value[:8], 16) + usec = int(value[8:], 16) + return float(f"{sec}.{usec}") + +tokens = ["6659cea087cd6" , "6659cea087cea"] +for token in tokens: + t = float(reverse_uniqid(token)) + d = datetime.datetime.fromtimestamp(t) + print(f"{token} - {t} => {d}") +``` + + +## Other + +Other bad ideas that are sometimes shipped into production. + +* `$token = md5($emailId).rand(10,9999);` +* `$token = md5(time()+123456789 % rand(4000, 55000000));` + +Generic identification and sandwitch attack: + +* [AethliosIK/reset-tolkien](https://github.com/AethliosIK/reset-tolkien) - Unsecure time-based secret exploitation and Sandwich attack implementation Resources + ```ps1 + reset-tolkien detect 660430516ffcf -d "Wed, 27 Mar 2024 14:42:25 GMT" --prefixes "attacker@example.com" --suffixes "attacker@example.com" --timezone "-7" + reset-tolkien sandwich 660430516ffcf -bt 1711550546.485597 -et 1711550546.505134 -o output.txt --token-format="uniqid" + ``` + ### References * [In GUID We Trust - Daniel Thatcher - October 11, 2022](https://www.intruder.io/research/in-guid-we-trust) -* [IDOR through MongoDB Object IDs Prediction - Amey Anekar - August 25, 2020](https://techkranti.com/idor-through-mongodb-object-ids-prediction/) \ No newline at end of file +* [IDOR through MongoDB Object IDs Prediction - Amey Anekar - August 25, 2020](https://techkranti.com/idor-through-mongodb-object-ids-prediction/) +* [[FR] Secret basé sur le temps non sécurisé et attaque par sandwich - Analyse de mes recherches et publication de l’outil “Reset Tolkien” - Tom CHAMBARETAUD / @AethliosIK - 2 apr 2024](https://www.aeth.cc/public/Article-Reset-Tolkien/secret-time-based-article-fr.html) +* [[EN] Unsecure time-based secret and Sandwich Attack - Analysis of my research and release of the “Reset Tolkien” tool - Tom CHAMBARETAUD / @AethliosIK - 2 apr 2024](https://www.aeth.cc/public/Article-Reset-Tolkien/secret-time-based-article-en.html) +* [Secret non sécurisé basé sur le temps et attaques par sandwich - Tom CHAMBARETAUD aka Aethlios](#) +* [Exploiting Weak Pseudo-Random Number Generation in PHP’s rand and srand Functions - Jacob Moore - Oct 18, 2023](https://medium.com/@moorejacob2017/exploiting-weak-pseudo-random-number-generation-in-phps-rand-and-srand-functions-445229b83e01) \ No newline at end of file