mirror of
https://github.com/swisskyrepo/PayloadsAllTheThings.git
synced 2024-12-13 14:52:53 +00:00
64 lines
No EOL
2.6 KiB
Markdown
64 lines
No EOL
2.6 KiB
Markdown
# Insecure Randomness
|
||
|
||
## Summary
|
||
|
||
* [GUID / UUID](#guid--uuid)
|
||
* [GUID Versions](#guid-versions)
|
||
* [Tools](#tools)
|
||
* [Mongo ObjectId](#mongo-objectid)
|
||
* [Tools](#tools)
|
||
* [References](#references)
|
||
|
||
## GUID / UUID
|
||
|
||
### GUID Versions
|
||
|
||
Version identification: `xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx`
|
||
The four-bit M and the 1- to 3-bit N fields code the format of the UUID itself.
|
||
|
||
| Version | Notes |
|
||
|----------|--------|
|
||
| 0 | Only `00000000-0000-0000-0000-000000000000` |
|
||
| 1 | based on time, or clock sequence |
|
||
| 2 | reserved in the RFC 4122, but ommitted in many implementations |
|
||
| 3 | based on a MD5 hash |
|
||
| 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
|
||
```ps1
|
||
$ guidtool -i 95f6e264-bb00-11ec-8833-00155d01ef00
|
||
UUID version: 1
|
||
UUID time: 2022-04-13 08:06:13.202186
|
||
UUID timestamp: 138691299732021860
|
||
UUID node: 91754721024
|
||
UUID MAC address: 00:15:5d:01:ef:00
|
||
UUID clock sequence: 2099
|
||
|
||
$ 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:
|
||
* **Timestamp** (4 bytes): Represents the ObjectId’s creation time, measured in seconds since the Unix epoch (January 1, 1970).
|
||
* **Machine Identifier** (3 bytes): Identifies the machine on which the ObjectId was generated. Typically derived from the machine's hostname or IP address, making it predictable for documents created on the same machine.
|
||
* **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.
|
||
|
||
### Tools
|
||
|
||
* [andresriancho/mongo-objectid-predict](https://github.com/andresriancho/mongo-objectid-predict) - Predict Mongo ObjectIds
|
||
```ps1
|
||
./mongo-objectid-predict 5ae9b90a2c144b9def01ec37
|
||
5ae9bac82c144b9def01ec39
|
||
5ae9bacf2c144b9def01ec3a
|
||
5ae9bada2c144b9def01ec3b
|
||
```
|
||
|
||
### 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/) |