Slack: Race Condition in account survey

There exists a race condition in the beginning survey, allowing a user to get $100 in credit multiple times. In my example, I made 2 asynchronous requests, and was credited with $200. POC: 1. Create a new slack team. 2. Set your password, and find the account creation survey. 3. Complete the...

Slack: Snooping into messages via email service

@uranium238 discovered a vulnerability with a 3rd party email integration provider which would allow messages in Slack email integrations to be leaked. We worked with the 3rd party to get this issue resolved, and performed a thorough investigation to confirm that this had never been exploited...

Slack: Code Injection in Slack's Windows Desktop Client leads to Privilege Escalation

Hi, This report is about a Code Injection vulnerability in Slack's Windows Desktop Client slack.exe that allows any local user to inject code into other user's Slack client. It has been verified on a fully patched english Windows 7 64bit running the latest available Slack Desktop Client 2.1.1...

Slack: Stored XSS(Cross Site Scripting) In Slack App Name

Hello Slack, This vulnerability is about a Stored Cross Site Scripting Slack Stored XSS In AppApp Name Vulnerable URLEdit App Page https://api.slack.com/apps/appid/general https://api.slack.com/apps/A21B3V9GA/general Vulnerable Parameter = name Note -Its also work on other user as well. Send this...

Slack: CSRF - Add optional two factor mobile number

Description ==================== Adding a mobile number for 2-factor authentication is vulnerable to CSRF, allowing an attacker to bypass 2-factor authentication. An attacker would be able to force the logged in user to add a new mobile number for 2-factor authentication. The attacker would then...

Slack: Creating Post on a restricted channel

Hi, I would like to report a privilege escalation issue in which a member of the team is able to create a post on a channel even if the permission to do so is denied to him by the admin.After the admin has limited the number of users who can post to a specific public channel,an unauthorized user...

Slack: a stored xss issue in https://files.slack.com

when making a BoxNote snippet with this xss payload: XSS" ; " when snippet made: and use the "view raw" xss payload will be executed my ex: link where xss payload executed: https://files.slack.com/files-pri/T027N7MK3-F1NCA92JF/XSSscriptimgsrcimgsrcsearchonerroralertXssmarqueeboxnote.boxnote that...

Slack: "a stored xss issue in share post menu"

good day: when a team mate named an xss payload: ex: " " that xss payload will execute when making a post then share it, to a team that has an xss payload named. that shared as a direct message please see screenshot when making post here: https://hunter22.slack.com/files/create/space...

Slack: Generate new Test token

We can generate a token test in any community that we are to use the API in the community although we are not community managers In the attached video, I show you how to generate a token in a community in which I am not administrator and I can check absolutely everything and even make use of the...

Slack: User can start call in a channel of an unpaid account

Found a super minor issue that allows a user to start a call in a channel of an unpaid account. Besides the minor financial incentive for an attacker, this doesn't have a super high impact. Wanted to let you know anyway since it's not possible through the UI by default. To reproce it, start by...

Slack: Unauthenticated Access to some old file thumbnails

File thumbnails which were uploaded before the implementation of auth checks do not have those checks retroactively applied. However, their URLs contain a secret which prevents guessing or brute-forcing of their location. Well, since you hid all the details which is why I requested disclosure in...

Slack: File upload over private IM channel

A team member can upload the files in the private IM chat channel of other members.This can be done by using the IM channel id. Please refer to the attached POC's. Let me know if any more details are needed...

Slack: [Screenhero] Subdomain takeover

Hi, I found out some neglected DNS records that can be exploited to takedown the subdomain of Slack's acquisition feedback.screenhero.com The security issue is that you have CNAME record that points feedback.screenhero.com to a screenhero.uservoice.com, but the problem is that the service is...

Slack Plugs Token Security Hole

Popular collaboration and communication firm Slack rushed to plugged a security hole in its platform Thursday that was leaking some of its users’ private chats and files for anyone to access. Slack, a leading tool used by companies to communicate internally, was alerted by security firm Detectify...

Slack: Stored XSS on team.slack.com using new Markdown editor of posts inside the Editing mode and using javascript-URIs

Hi, I noticed while looking at an old article I made a while ago that some links were actually inserted as javascript:-links. Doing some modifications to these actually revealed that inside editing mode, no protection is added for getting arbitrary scripts to run. This means that by catching the...

Linux Vulnerability Scanner: Vuls

Vulnerability scanner for Linux, agentless, written in golang For a system administrator, having to perform security vulnerability analysis and software update on a daily basis can be a burden. To avoid downtime in production environment, it is common for system administrator to choose not to use...

Slack: Access to some Slack workspace metadata and settings available to unauthorized parties

In April 2016, @secalert alerted us to a vulnerability which may have allowed access to some Slack workspace metadata and settings to unauthorized parties. We implemented an initial fix within minutes, and a complete fix within two weeks. Nothing further is required from users to be protected...

Slack: Authentication bypass leads to sensitive data exposure (token+secret)

@secalert discovered an information disclosure on our server which took advantage of an authorization error that allowed the viewing of sensitive information on the server. We mitigated the issue and no longer expose such information, and performed an investigation to verify that no unauthorized...

Slack: Bypass two-factor authentication

If a user set 2FA, a user has to enter verification code when a user tries to reset password. Under the "Password Reset" page, a user can enter wrong two-factor authentication code many times. I said "many times" because your bug bounty policy stated... Exclusions Issues found through automated...

Slack: an xss issue in https://hunter22.slack.com/help/requests/793043

good day: i found an xss issue when making a help request.. https://hunter22.slack.com/help/requests/new with this xss payload: Click here click this link when try to comment the xss payload , then upon clicking xss payload executed...