CVE-2024-39878 in TeamCity
Summary
by MITRE • 07/01/2024
In JetBrains TeamCity before 2024.03.3 private key could be exposed via testing GitHub App Connection
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Analysis
by VulDB Data Team • 09/17/2024
The vulnerability identified as CVE-2024-39878 affects JetBrains TeamCity versions prior to 2024.03.3 and represents a critical security flaw in the handling of GitHub App connections. This issue specifically manifests when testing GitHub App connections within the TeamCity environment, where private key material intended for secure authentication purposes becomes inadvertently exposed through the testing process. The vulnerability stems from insufficient input validation and improper handling of sensitive cryptographic material during connection testing operations, creating an attack surface that could be exploited by malicious actors with access to the TeamCity instance or network traffic monitoring capabilities.
The technical implementation of this flaw involves the improper management of private key data during the GitHub App connection validation process. When users test their GitHub App connections through TeamCity's interface, the system fails to properly sanitize or isolate the private key information, potentially logging or transmitting this sensitive data in cleartext or in formats that reveal the cryptographic material. This behavior violates fundamental security principles for handling cryptographic keys and represents a direct violation of secure coding practices outlined in various security frameworks. The vulnerability can be categorized under CWE-312 (Sensitive Data Exposure) and potentially CWE-200 (Information Exposure) as it leads to unauthorized disclosure of private key information that should remain protected.
The operational impact of this vulnerability extends beyond simple information disclosure, as private keys are critical components for authenticating and authorizing access to GitHub repositories and resources. If exploited, an attacker could gain unauthorized access to repositories, perform malicious actions on behalf of the legitimate user, or potentially escalate privileges within the CI/CD pipeline. The exposure of private keys could lead to complete compromise of the software supply chain, enabling attackers to inject malicious code into the build process, modify source code repositories, or gain access to other systems connected through the compromised TeamCity instance. This risk is particularly severe in enterprise environments where TeamCity often serves as a central hub for automated builds and deployments, making the exposure of private keys a significant threat to overall security posture.
Organizations using affected TeamCity versions should immediately implement mitigations including upgrading to TeamCity 2024.03.3 or later, which contains the necessary patches to address this vulnerability. Additionally, administrators should review existing GitHub App configurations and regenerate private keys for any connections that may have been tested while vulnerable. Network monitoring should be enhanced to detect potential exfiltration of sensitive data, and access controls should be strengthened around TeamCity administrative interfaces. The remediation process should also include security awareness training for developers who may be testing GitHub connections, emphasizing the importance of proper key management and avoiding exposure of sensitive credentials during testing operations. This vulnerability highlights the critical need for proper input validation and secure handling of cryptographic materials in CI/CD environments, aligning with ATT&CK technique T1552.001 (Credentials In Files) and other credential exposure tactics that attackers commonly leverage in supply chain compromises.