CVE-2023-28433

Workarounds

There are no known workarounds

References

The vulnerable code:

// minio/cmd/generic-handlers.go
// Check if the incoming path has bad path components,
// such as ".." and "."
// SlashSeparator -> /
// dotdotComponent -> ..
// dotComponent -> .
func hasBadPathComponent(path string) bool {
  path = strings.TrimSpace(path)
  for _, p := range strings.Split(path, SlashSeparator) {
    switch strings.TrimSpace(p) {
    case dotdotComponent:
      return true
    case dotComponent:
      return true
    }
  }
  return false
}

All users on Windows are impacted. MinIO fails to filter the \ character, which allows for arbitrary object placement across
buckets. As a result, a user with low privileges, such as an access key, service account, or STS credential, which only has permission to PutObject in a specific bucket, can create an admin user.

CVE-2023-28433 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-202303200735); upgrading removes the vulnerable code path.

Kodem intelligence

There are two patches that fix this problem comprehensively

commit b3c54ec81e0a06392abfb3a1ffcdc80c6fbf6ebc
Author: Harshavardhana <[email protected]>
Date:   Mon Mar 20 13:16:00 2023 -0700

    reject object names with '\' on windows (#16856)

commit 8d6558b23649f613414c8527b58973fbdfa4d1b8
Author: Harshavardhana <[email protected]>
Date:   Mon Mar 20 00:35:25 2023 -0700

    fix: convert '\' to '/' on windows (#16852)

1. What is CVE-2023-28433? CVE-2023-28433 is a high-severity security vulnerability in github.com/minio/minio (go), affecting versions < 0.0.0-202303200735. It is fixed in 0.0.0-202303200735.
2. How severe is CVE-2023-28433? CVE-2023-28433 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/minio/minio are affected by CVE-2023-28433? github.com/minio/minio (go) versions < 0.0.0-202303200735 is affected.
4. Is there a fix for CVE-2023-28433? Yes. CVE-2023-28433 is fixed in 0.0.0-202303200735. Upgrade to this version or later.
5. Is CVE-2023-28433 exploitable, and should I be worried? Whether CVE-2023-28433 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2023-28433 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2023-28433? Upgrade github.com/minio/minio to 0.0.0-202303200735 or later.