Kiota: Code injection through doc-comment delimiter reformation in Kiota Java and PHP generators

Overview

Kiota is an OpenAPI based HTTP Client code generator. From 0.5.0 until 1.35.0, Kiota's Java and PHP documentation-comment sanitizers delete block-comment terminators rather than neutralizing them, allowing overlapping characters to reform a terminator and place attacker-controlled OpenAPI text outside a generated documentation comment. The Java sanitizer also removes non-ASCII characters after deleting terminators, which can create a new terminator during normalization. Exploitation requires a developer or build pipeline to generate source from the malicious description and then compile and load the Java output or load the PHP output, after which injected code executes in the consuming application or build environment context. The version range is based on the Java defect and does not assert that PHP generation existed in every affected release. This issue is fixed in version 1.35.0.

Affected

• kiota >= 0.5.0, < 1.35.0
• Microsoft.OpenApi.Kiota >= 0.5.0, < 1.35.0
• Microsoft.OpenApi.Kiota.Builder >= 0.5.0, < 1.35.0

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.