GHSA-7cc2-r658-7xpf CVE-2024-27918 GO-2024-2602
Coder's OIDC authentication allows email with partially matching domain to register
- Severity
- 8.2 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 0.97%
- Chance of exploitation in the next 30 days. Higher than 61.71% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-20 Improper Input Validation
- Fix
2.8.4- Upgrade github.com/coder/coder/v2 to this version or later
Description
Summary
A vulnerability in Coder's OIDC authentication could allow an attacker to bypass the CODER_OIDC_EMAIL_DOMAIN verification and create an account with an email not in the allowlist. Deployments are only affected if the OIDC provider allows users to create accounts on the provider (such as public providers like google.com).
Details
During OIDC registration, the user's email was improperly validated against the allowed CODER_OIDC_EMAIL_DOMAINs. This could allow a user with a domain that only partially matched an allowed domain to successfully login or register (e.g. user@exploitcorp.com would match the allowed domain corp.com).
An attacker could register a domain name that exploited this vulnerability and register on a Coder instance with a public OIDC provider.
Impact
Coder instances with OIDC enabled and protected by the CODER_OIDC_EMAIL_DOMAIN configuration.
Coder instances using a private OIDC provider are not affected, as arbitrary users cannot register through a private OIDC provider without first having an account on the provider.
Public OIDC providers (such as google.com without permitted domains set on the OAuth2 App) are impacted.
GitHub authentication and external authentication are not impacted.
Was my deployment impacted?
To check if your deployment was exploited:
- View the audit log on your deployment for unexpected registered users (using the
action:registerfilter) - Check the users list for unexpected users
- Users created via this exploit will have a domain that ends with one of the allowed domains but doesn’t fully match (e.g.
@exploitcorp.cominstead of@corp.com)
- Users created via this exploit will have a domain that ends with one of the allowed domains but doesn’t fully match (e.g.
Patched Versions
This vulnerability is remedied in
- v2.8.4
- v2.7.3
- v2.6.1
All versions prior to these patches are affected by the vulnerability. It is recommended that customers upgrade their deployments as soon as possible if they are utilizing OIDC authentication with the CODER_OIDC_EMAIL_DOMAIN setting.
Thanks
References
https://github.com/coder/coder/security/advisories/GHSA-7cc2-r658-7xpf https://github.com/coder/coder/commit/4439a920e454a82565e445e4376c669e3b89591c https://nvd.nist.gov/vuln/detail/CVE-2024-27918
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| github.com/coder/coder | <= 0.27.3 |
No fix yet |
| github.com/coder/coder | all versions |
No fix yet |
| github.com/coder/coder/v2 | >= 2.8.0, < 2.8.4 |
2.8.4 |
| github.com/coder/coder/v2 | >= 2.7.0, < 2.7.3 |
2.7.3 |
| github.com/coder/coder/v2 | < 2.6.1 |
2.6.1 |
| github.com/coder/coder/v2 | < 2.6.1>= 2.7.0, < 2.7.3>= 2.8.0, < 2.8.4 |
2.6.12.7.32.8.4 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
github.com/coder/coder/v2 Go → 2.8.4
- go
go get github.com/coder/coder/v2@v2.8.4 && go mod tidy
Severity breakdown
CVSS 3.1 8.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- High
Weakness
CWE-20: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How to prevent it
- Architecture and Design: Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses. [REF-1109] [REF-1110] [REF-1111]
- Architecture and Design: Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Architecture and Design, Implementation: Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server. Even though client-side checks provide minimal benefits with respect to server-side security, they are still useful. First, they can support intrusion detection. If the server receives input that should have been rejected by the client, then it may be an indication of an attack. Second, client-side error-checking can provide helpful feedback to the user about the expectations for valid input. Third, there may be a reduction in server-side processing time for accidental input errors, although this is typically a small savings.
- Implementation: When your application combines data from multiple sources, perform the validation after the sources have been combined. The individual data elements may pass the validation step but violate the intended restrictions after they have been combined.
- Implementation: Be especially careful to validate all input when invoking code that crosses language boundaries, such as from an interpreted language to native code. This could create an unexpected interaction between the language boundaries. Ensure that you are not violating any of the expectations of the language with which you are interfacing. For example, even though Java may not be susceptible to buffer overflows, providing a large argument in a call to native code might trigger an overflow.
- Implementation: Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180, CWE-181). Make sure that your application does not inadvertently decode the same input twice (CWE-174). Such errors could be used to bypass allowlist schemes by introducing dangerous inputs after they have been checked. Use libraries such as the OWASP ESAPI Canonicalization control. Consider performing repeated canonicalization until your input does not change any more. This will avoid double-decoding and similar scenarios, but it might inadvertently modify inputs that are allowed to contain properly-encoded dangerous content.
- Implementation: When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.
References
Advisories
Packages
Other links
- github.com/coder/coder/security/advisories/GHSA-7cc2-r658-7xpf
- github.com/coder/coder/commit/1171ce7add017481d28441575024209ac160ecb0
- github.com/coder/coder/commit/2ba84911f8b02605e5958d5e4a2fe3979ec50b31
- github.com/coder/coder/commit/2d37eb42e7db656e343fe1f36de5ab1a1a62f4fb
- github.com/coder/coder/commit/4439a920e454a82565e445e4376c669e3b89591c
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-h58c-xccx-75m3 Coder: Stored HTML injection via unescaped ApplicationName and LogoURL appearance settings | Medium | Also affects github.com/coder/coder |
| GHSA-8fxq-53rx-ph5f Coder: Login endpoint user enumeration via timing-defense placeholder in password comparison | Medium | Also affects github.com/coder/coder |
| GHSA-qrwj-vh9x-gw5v Coder's workspace agent API insecure redirect handling allowed cross-agent file read and write | High | Also affects github.com/coder/coder |
| GHSA-5wg6-jmq2-53pw Coder's workspace app CORS origin check can be bypassed via UUID-based subdomain spoofing | Medium | Also affects github.com/coder/coder |
| GHSA-7qw2-f75v-62f7 Coder vulnerable to stored HTML injection via workspace agent logs in AgentLogLine component | Medium | Also affects github.com/coder/coder |
| GHSA-84rm-42xw-mx52 Coder's AI Bridge Proxy skips TLS certificate verification in default configuration | High | Also affects github.com/coder/coder |
| GHSA-wqxv-w64v-5wh6 Suspended Coder users retain access to AI Bridge LLM proxy endpoints | Medium | Also affects github.com/coder/coder |
| GHSA-f5vp-w269-392g Coder vulnerable to denial of service via unbounded request body in AI Bridge provider endpoints | Medium | Also affects github.com/coder/coder |
Credits: arcz, maxammann
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