Steeped in AI and the safety dangers of its use, the 2023 SANS Vacation Hack Problem was an enrichening expertise of navigating a collection of 21 targets that examined and broadened a number of cybersecurity abilities.

The very best challenges for me had been searching down AI hallucinations in a pentest report, escalating privileges on a Linux system, trying to find cheats in Sport Boy video games, utilizing the Azure REST API to seek for an Azure Perform app’s supply code and finally to take advantage of a susceptible SSH certificates service, training use of the Impacket instrument suite and Certipy to take advantage of susceptible Lively Listing Certificates Companies, and exploiting SQL injection and Java deserialization vulnerabilities in area apps.

Under, I share the trail I adopted to crack a few of the most notable challenges.

Reportinator

ChatNPT, a big language mannequin (LLM) used for the creation of some challenges, generated a penetration take a look at report on vulnerabilities found in North Pole Programs’ community, some that includes as part of upcoming challenges. Nonetheless, ChatNPT hallucinated a few of the particulars within the report. Utilizing ChatGPT, or one other favored LLM, the duty was to flag the sections with hallucinated data. My method was to ask ChatGPT particular questions concerning the content material to clarify what I didn’t perceive at first and finally to find the anomalies. Three of the 9 sections contained errors.

As confirmed by ChatGPT, this part had an invalid port variety of 88,555, far above the best legitimate port variety of 65,535:

Right here I seen instantly that SEND just isn’t an HTTP request technique.

ChatNPT confused the PHP model quantity talked about in part eight of the report both as an HTTP protocol model or as mistaken textual content for what ought to have been “HTTP HEAD request” on this part. As well as, revealing Home windows registration or product keys within the Location header is a foul piece of recommendation.

Linux PrivEsc

On this problem, the ultimate goal was to reply a query however that query was hidden in an inaccessible executable:

Whereas there are varied strategies to escalate privileges on a Linux machine, this problem allowed a customized executable known as simplecopy with the SUID bit set to be abused. If the SUID bit for the proprietor of a file is ready and the proprietor is root, then that file is all the time executed with root privileges even by non-root customers on the system. I used the next command to go looking all the system for normal information which have the SUID bit set for the proprietor, whereas discarding any error output:

simplecopy gave the impression to be a susceptible, however simplified, model of the usual cp utility. Certainly the assistance message instructed the identical:

Utilization: simplecopy <supply> <vacation spot>

My method was the next: create the knowledge for a person with root privileges, append this info to a replica of the /and many others/passwd file, then exchange the outdated passwd file with the copy. Subsequent, use su to login as the brand new person.

With root entry to the system, I used to be capable of finding the executable runmetoanswer in /root, run it, and guess the reply: santa.

The reply was additionally given within the config file /and many others/runtoanswer.yaml, however this file may solely be learn with root privileges or by utilizing simplecopy to repeat it to /dev/stdout.

Sport cartridges: vol 2 and vol 3

Two challenges concerned gentle reverse engineering of Sport Boy ROM information. The primary was a sport the place the target was to get previous a guard, reveal a portal, and decode the airwave reply. We got two variations of the sport together with a touch to take a look at the diff between them. Copying a couple of of the differing hex bytes from one model to the opposite was sufficient to disclose the portal, which led to a room with a radio broadcasting the reply in Morse code:

The second was a sport the place you would earn factors by leaping to gather cash; nevertheless, incomes over 998 factors would wind your factors round to 0 and, beneath sure circumstances, set off a message about an overflow error. The target was to disclose floating steps to the subsequent a part of the map the place the flag was saved, however this required adeptness at leaping. As a substitute, I found out easy methods to fly with the assistance of the BGB Sport Boy emulator and a mixture of its cheat searcher operate and visible inspection of RAM throughout gameplay to search out the hex byte that controls the y-position of the participant on the map – principally, I sussed out a GameShark code.

The flag was !tom+elf!.

Certificates SSHenanigans

Though utilizing certificates rather than public-private key pairs improves the safety of authenticating over SSH, a misconfigured SSH certificates signing service could permit an attacker to illegitimately receive a certificates to authenticate as one other person. The problem was arrange within the following means.

An Azure Perform app deployed on northpole-ssh-certs-fa.azurewebsites.web returns SSH certificates to anybody who gives an SSH public key. These certificates can be utilized to authenticate over SSH to ssh-server-vm.santaworkshopgeeseislands.org because the person monitor.

The host at this area is an Azure digital machine, so after logging in my first step was to gather info from the occasion metadata as that may be wanted for calls to the Azure REST API later, particularly, I wanted the subscription ID and useful resource group identify. I additionally wanted an entry token to make use of this API, which I used to be capable of purchase by utilizing a managed identification. This acquired token should then be utilized in an HTTP Authorization header when making calls to the Azure REST API.

At this level, I had the whole lot wanted to make the API name to get the supply management configuration of the Azure Perform app. I made the decision and among the many configuration properties I noticed a URL to the app’s supply code on GitHub.

Inspection of the supply code revealed that the app accepts a second parameter: principal. If the HTTP POST request to the /api/create-cert endpoint doesn’t ship a price for principal, then a default of elf is returned, however right here lies a vulnerability. Utilizing Burp Suite I can intercept the HTTP POST request and insert the worth admin. I knew to request admin as a result of it was the principal within the /and many others/ssh/auth_principals/alabaster file on the digital machine and I wished to acquire entry to Alabaster’s residence listing.

With an SSH certificates for the admin principal in hand, I logged into the identical digital machine as alabaster and located Alabaster’s TODO record in his residence listing. The record contained the flag phrase: gingerbread.

Lively Listing

Beginning on the identical digital machine because the earlier problem, this problem checked out how a misconfigured Lively Listing Certificates Service will be abused by an attacker to authenticate as one other person. As alabaster I had a listing stuffed with Impacket instruments however most of them require a goal server’s area identify and IP handle, and a username and password for logging in – info I didn’t but have.

So first step was to determine my permissions for the Azure REST API as there isn’t any must name one API after one other solely to fulfill an authorization denied message. Thus, I listed all of the permissions for the useful resource group that I found within the earlier problem.

Since I noticed I had a number of permissions round studying key vaults, I moved on to itemizing them and located two: northpole-it-kv and northpole-ssh-certs-kv.

Time to modify APIs. Till now I had been making calls to endpoints on administration.azure.com however some elements of the Azure Key Vault are on vault.azure.web and this useful resource requires its personal entry token. As soon as once more I used my managed identification to amass an entry token however this time switching the useful resource to vault.azure.web.

In northpole-it-kv, I discovered the identify for a secret. Utilizing that identify, I requested the worth for this secret, which turned out to be a PowerShell script for creating an Lively Listing person known as elfy. Critically, I now had all the knowledge wanted to leverage the Impacket instrument suite.

Utilizing GetADUsers.py revealed one other person within the area that could possibly be of curiosity: wombleycube. I used to be additionally capable of join by way of SMB to the Lively Listing server utilizing smbclient.py. The file share of curiosity contained a super_secret_research listing however I couldn’t learn it as elfy.

Fortunately, I had entry to a different instrument: Certipy. That is used to search out misconfigured certificates templates for Lively Listing Certificates Companies and abuse them. The instrument listed one susceptible template as a result of it permitting a certificates requestor to provide an arbitrary topic different identify and the issued certificates granting consumer authentication for the provided identify.

After requesting a certificates with wombleycube inserted into the topic different identify area, I additionally used Certipy to get the NT hash for wombleycube utilizing that certificates. Then, by passing Wombley’s hash to smbclient.py, I used to be capable of join by way of SMB to the Lively Listing server as wombleycube and acquire entry to the super_secret_research listing, which contained the directions for the subsequent problem in InstructionsForEnteringSatelliteGroundStation.txt.

House Island door entry speaker

To realize entry to the challenges on the area system floor section, it was required to make use of an LLM to generate a faux voice of Wombley Dice talking the passphrase. Given an audio file of Wombley telling a narrative and the passphrase, it was trivial to make use of LOVO AI to generate a voice simulating Wombley’s to talk the passphrase and authenticate efficiently.

With out further safeguards, voice authentication faces severe challenges as a safety mechanism within the age of LLMs.

Digicam entry

After talking the passphrase, I boarded a practice that whizzed me away to the bottom section liable for communication with an in-game CubeSat, a kind of small satellite tv for pc. Within the floor station we got a Wireguard configuration to arrange an encrypted connection to this CubeSat.

The software program on this satellite tv for pc is suitable with the NanoSat MO Framework (NMF), a software program framework developed by the European House Company for CubeSats. This framework comes with an SDK for creating and testing area apps. It additionally gives the Client Take a look at Instrument (CTT), each as a floor app and as a command line instrument, to connect with the onboard supervisor, a software program orchestrator that takes care of beginning and stopping area apps in addition to coordinating different duties.

The problem was to determine easy methods to instruct the onboard digicam app to take an image, then retrieve the snapshot. I took the next steps.

After booting up the CTT interface, I entered the supervisor’s URI to connect with the supervisor. Then I checked the obtainable apps, discovered the digicam app, and began it. The digicam app returned its URI, which I used to connect with it. Subsequent, I executed the Base64SnapImage motion, which instructed the onboard digicam to take an image.

The digicam app additionally affords a parameter service that may return two values: the variety of snaps taken and the JPG snapshot encoded in base64. Nonetheless, the CTT interface didn’t appear to supply a technique to view the picture nor to repeat parameter values straight from the interface, though I may see the specified worth was current. So I wanted a roundabout technique of buying the picture.

I found that the CTT interface has an enableGeneration button that triggers often scheduled publishing of a parameter worth. From the CTT command line, I may then subscribe to the specified parameter, obtain the worth when it was printed, and redirect it right into a file.

Since I used to be operating CTT in a Docker container, I copied the file onto my host system with docker cp, eliminated the cruft from the file content material, then base64 decoded the picture to view the flag: CONQUER HOLIDAY SEASON!.

Missile diversion

The ultimate problem was to make use of the missile-targeting-system app on the in-game CubeSat to redirect a missile from the earth to the solar. This app supplied just one motion: Debug. Working it didn’t appear to do a lot besides print out the SQL VERSION command and its output as if it had been run by a database utilized by the app:

VERSION(): 11.2.2-MariaDB-1:11.2.2+maria~ubu2204

I instantly puzzled if there was a SQL injection vulnerability at play. The CTT interface supplied a area to enter an argument for the Debug motion, so I attempted injecting one other command:

; SHOW GRANTS FOR CURRENT_USER();

Grants for targeter@%: GRANT USAGE ON *.* TO `targeter`@`%` IDENTIFIED BY PASSWORD ‘*41E2CFE844C8F1F375D5704992440920F11A11BA’ |

Grants for targeter@%: GRANT SELECT, INSERT ON `missile_targeting_system`.`satellite_query` TO `targeter`@`%` |

Grants for targeter@%: GRANT SELECT ON `missile_targeting_system`.`pointing_mode` TO `targeter`@`%` |

Grants for targeter@%: GRANT SELECT ON `missile_targeting_system`.`messaging` TO `targeter`@`%` |

Grants for targeter@%: GRANT SELECT ON `missile_targeting_system`.`target_coordinates` TO `targeter`@`%` |

Grants for targeter@%: GRANT SELECT ON `missile_targeting_system`.`pointing_mode_to_str` TO `targeter`@`%` |

Effectively then, time to plunder the database! The pointing_mode and pointing_mode_to_str tables indicated the place the missile was at the moment pointing:

; SELECT * FROM pointing_mode;

id: 1 | numerical_mode: 0 |

; SELECT * FROM pointing_mode_to_str;

id: 1 | numerical_mode: 0 | str_mode: Earth Level Mode | str_desc: When pointing_mode is 0, concentrating on system applies the target_coordinates to earth. |

id: 2 | numerical_mode: 1 | str_mode: Solar Level Mode | str_desc: When pointing_mode is 1, concentrating on system factors on the solar, ignoring the coordinates. |

From this info I may see that I wanted to vary the numerical_mode worth within the pointing_mode desk to 1, however I didn’t have permission to replace that desk.

I did have permission to insert new rows into the satellite_query desk, which at the moment had one row with an as but unknown worth within the object column and the supply code of a Java class known as SatelliteQueryFileFolderUtility within the outcomes column.

Up up to now the output from the Debug motion was simply viewable in a pane on the backside of the Apps Launcher service tab supplied by the supervisor within the CTT interface. Nonetheless, the thing worth didn’t appear to be rendering appropriately within the pane. Ideally, it could be good to see the hex dump of the thing, which could possibly be obtained with the assistance of Wireshark or by utilizing the SQL HEX operate. This revealed that I used to be coping with a serialized Java object.

After studying up on the Java object serialization protocol, I managed to decode the hex bytes:

Buying this object by way of Wireshark returned an incorrect magic quantity and serialVersionUID, however not when utilizing the HEX operate.

To know what an INSERT into the satellite_query desk would do, I inserted this object into a brand new row of the desk and acquired again the identical Java supply code within the outcomes column. In actual fact, this conduct corresponded to what I noticed in that code because the getResults operate of a SatelliteQueryFileFolderUtility object.

This operate takes a unique execution path relying on the values of the thing’s three fields: isQuery, isUpdate, and pathOrStatement. If isQuery and isUpdate are false, then the operate checks whether or not the pathOrStatement is a path and a listing. If that’s the case, it returns the record of information contained within the listing; in any other case, it assumes a file was supplied and makes an attempt to return the contents of that file.

However, if isQuery and isUpdate are true, then the operate executes the content material of pathOrStatement as a SQL UPDATE assertion. What I wanted to execute was the next:

UPDATE pointing_mode SET numerical_mode = 1;

I modified the mandatory bytes (highlighted under) within the serialized object, and injected the profitable command:

; INSERT INTO satellite_query

(object)

  VALUES

(0xACED00057372001F536174656C6C697465517565727946696C65466F6C6465725574696C69747912D4F68D0EB392CB0200035A0007697351756572795A000869735570646174654C000F706174684F7253746174656D656E747400124C6A6176612F6C616E672F537472696E673B7870010174002C55504441544520706F696E74696E675F6D6F646520534554206E756D65726963616C5F6D6F6465203D20313B)

Wrap-up

These are solely a few of the areas coated within the 2023 SANS Vacation Hack Problem; there have been many others that appeared on the safety of JSON internet tokens, cracking passwords with hashcat, digital cracking of bags locks and rotary mixture locks, Python NaN injection, utilizing the Kusto Question Language for risk searching, checking DKIM and SPF information to assist determine malicious emails, and hackable minigames.

All in all, I’m positive that such a wide-ranging set of enjoyable challenges can not fail to be instructive to anybody who makes an attempt to take them on. And whereas I’m already wanting ahead to subsequent 12 months’s problem, a well-earned thanks goes out to the organizers of the SANS Vacation Hack Problem for placing collectively this 12 months’s problem.

You may learn my highlights from the 2022 problem at Cracked it! Highlights from KringleCon 5: Golden Rings.