Bubble.io 0-Day Vulnerability Exposes User Data Through Elasticsearch Query Manipulation

Bubble.io Vulnerability Exposes User Data to Potential Exploits: A Deep Dive into Elasticsearch Flaws

Bubble.io, a widely-used no-code development platform that allows users to create fully functional applications without needing to write a single line of code, has recently been found to have a critical zero-day vulnerability. This flaw could expose thousands of applications to potential data breaches, allowing attackers to manipulate Elasticsearch queries and access sensitive user information.

Discovered by security researchers, the vulnerability lies within the platform’s handling of Elasticsearch queries. By exploiting weaknesses in the way Bubble.io encrypts search requests, attackers can bypass platform safeguards and execute arbitrary queries, leading to the unauthorized extraction of sensitive data, including email addresses, payment details, and hashed passwords.

Technical Breakdown: The Mechanics of the Exploit

The exploit hinges on weaknesses in Bubble.io’s cryptographic practices and how the platform encrypts and processes Elasticsearch queries. Elasticsearch is a key component of Bubble.io’s infrastructure, used to perform searches within applications hosted on the platform. However, the flaw in the encryption mechanism leaves applications vulnerable to malicious queries.

The encryption methods used by Bubble.io—AES-CBC and PBKDF2_HMAC—are supposed to protect Elasticsearch requests by encrypting them with a timestamp and an initialization vector (IV). However, the problem arises from the use of predictable and hardcoded IVs, which are reused across all Bubble.io applications. These reusable IVs make it easier for attackers to decrypt the queries and manipulate them for malicious purposes.

How the Exploit Works: Decryption and Query Manipulation

The structure of a typical encrypted request consists of three Base64-encoded components:

1. y: A timestamp, which is encoded in Base64.

2. x: The initialization vector (IV), which is also encoded in Base64.

3. z: The encrypted query, derived from the app’s name (extracted from the HTTP header X-Bubble-Appname) and the hardcoded IVs, such as "po9" and "fl1."

In normal circumstances, these elements are encrypted using AES and PBKDF2_HMAC, providing a level of protection. However, since the IVs are predictable and reused across different applications, attackers can exploit this flaw to decrypt the query.

Decryption Process

Here’s a simplified breakdown of how attackers can decrypt the payload:

1. Extract the app name from the HTTP headers sent along with the request.

2. Use the hardcoded IVs ("po9" and "fl1") that are shared across all applications hosted on Bubble.io.

3. Apply AES decryption with the app name and IVs to reveal the raw Elasticsearch query hidden in the payload.

Once decrypted, attackers gain access to the underlying Elasticsearch query, allowing them to modify it and bypass restrictions placed on query results. The manipulated query could request an unlimited amount of data, thus enabling attackers to extract entire user databases.

Demonstrating the Exploit: From Limited Data to Full Data Extraction

To illustrate how attackers can manipulate the payload, let’s look at an example of a typical query designed to fetch a single user’s data, such as their email address:

{
  "query": {
    "term": {
      "email": "user@example.com"
    }
  },
  "size": 1
}

This query is harmless, as it only fetches the data of one user. However, by altering the payload, attackers can bypass the limits and retrieve all user data stored in the Elasticsearch database. The altered query might look like this:

{
  "query": {
    "match_all": {}
  },
  "size": 10000
}

In this manipulated version of the query, the attacker requests data from all users in the database, with no size limit. This could result in the exposure of sensitive information, including:

• Email addresses

• Hashed passwords

• Payment details

• Other private user data

Potential Risks and Impact

The vulnerability exposes a range of serious risks for organizations using Bubble.io to build their applications. Some of the key risks include:

1. Full Database Extraction
Attackers can extract entire Elasticsearch databases, bypassing any limits on returned results. This could lead to the mass exposure of user data, including sensitive information like personal identifiers and financial data.

2. Cross-Tenant Vulnerabilities
Because Bubble.io uses shared hosting infrastructure for its no-code platform, a single application exploit could potentially allow attackers to pivot to other applications hosted on the platform. This increases the risk of cross-tenant attacks, where data from multiple unrelated applications could be exposed in a single exploit.

3. Bypass of Security Controls
The flaw also undermines security measures like query sanitization and result limits. Normally, these controls would restrict how much data could be returned in a single query, but the exploit allows attackers to bypass these restrictions entirely.

4. Difficulty in Mitigation
Given that the flaw is deeply rooted in the platform’s cryptographic infrastructure, addressing it may require significant changes to Bubble.io’s core systems. This makes it more difficult for developers to mitigate the issue on their own

Security Measures and Developer Recommendations

As of April 18, 2025, Bubble.io has yet to release an official patch for this vulnerability. Researchers strongly recommend that developers take immediate steps to protect their applications. Some key actions include:

1. Auditing Elasticsearch Configurations: Developers should review their Elasticsearch configurations and ensure that they are not relying on default, hardcoded IVs or predictable encryption mechanisms. Using more secure encryption techniques is essential.

2. Rotating API Keys and Sensitive Data: To mitigate the risk of exploitation, developers should regularly rotate API keys and sensitive data, ensuring that old keys can no longer be used by attackers to access the platform.

3. Monitoring Logs for Unusual Activity: Developers should carefully monitor application logs for signs of abnormal search activity or unauthorized queries. Such monitoring can help identify malicious attempts to exploit the vulnerability.

The Bigger Picture: Risks in No-Code Platforms

This vulnerability in Bubble.io highlights a broader issue with no-code platforms: their lack of transparency and the hidden security risks they present. While no-code platforms like Bubble.io enable users with little technical expertise to build complex applications, they often obscure critical infrastructure components, including security protocols.

Many no-code platforms abstract away the underlying code and systems, making it difficult for developers to fully understand how their applications work or to identify potential vulnerabilities. While this abstraction simplifies the development process, it also increases the risk of unnoticed security flaws.

As Bubble.io's vulnerability shows, ease of use should never come at the expense of security. Developers using these platforms must be proactive in understanding the potential risks and implementing the necessary measures to safeguard sensitive data.

 A Call for Vigilance in No-Code Development

No-code platforms are revolutionizing the app development landscape, making it easier for non-technical individuals to create powerful applications. However, as the Bubble.io vulnerability shows, security cannot be taken for granted in this new era of development.

Developers using no-code tools must stay vigilant, conducting third-party audits, following best practices for encryption, and ensuring that security is not sacrificed for convenience. As more organizations adopt no-code solutions, it is crucial to understand the underlying security implications of these platforms and take the necessary steps to mitigate risks.

Bubble.io’s zero-day vulnerability serves as a timely reminder In no-code development, security is still everyone’s responsibility.