CVE-2023-51651

References

RFC 3986 - https://datatracker.ietf.org/doc/html/rfc3986

For more information

If you have any questions or comments about this advisory, please contact AWS's Security team.

Within the scope of requests to S3 object keys and/or prefixes containing a Unix double-dot, a URI path traversal is possible. The issue exists in thebuildEndpoint method in the RestSerializer component of the AWS SDK for PHP v3 prior to 3.288.1. The buildEndpoint method relies on the Guzzle Psr7 UriResolver utility, which strips dot segments from the request path in accordance with RFC 3986. Under certain conditions, this could lead to an arbitrary object being accessed.

Versions of the AWS SDK for PHP v3 before 3.288.1 are affected by this issue.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2023-51651 has a CVSS score of 6.0 (Medium). The vector is requires local access, high 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 (3.288.1); upgrading removes the vulnerable code path.

Kodem intelligence

Upgrade to the AWS SDK for PHP >= 3.288.1, if you are on version < 3.288.1.

1. What is CVE-2023-51651? CVE-2023-51651 is a medium-severity path traversal vulnerability in aws/aws-sdk-php (composer), affecting versions < 3.288.1. It is fixed in 3.288.1. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2023-51651? CVE-2023-51651 has a CVSS score of 6.0 (Medium). 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 aws/aws-sdk-php are affected by CVE-2023-51651? aws/aws-sdk-php (composer) versions < 3.288.1 is affected.
4. Is there a fix for CVE-2023-51651? Yes. CVE-2023-51651 is fixed in 3.288.1. Upgrade to this version or later.
5. Is CVE-2023-51651 exploitable, and should I be worried? Whether CVE-2023-51651 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-2023-51651 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-2023-51651? Upgrade aws/aws-sdk-php to 3.288.1 or later.