CVE-2023-51451 in symbolicator
Summary
by MITRE • 12/22/2023
Symbolicator is a service used in Sentry. Starting in Symbolicator version 0.3.3 and prior to version 21.12.1, an attacker could make Symbolicator send GET HTTP requests to arbitrary URLs with internal IP addresses by using an invalid protocol. The responses of those requests could be exposed via Symbolicator's API. In affected Sentry instances, the data could be exposed through the Sentry API and user interface if the attacker has a registered account. The issue has been fixed in Symbolicator release 23.12.1, Sentry self-hosted release 23.12.1, and has already been mitigated on sentry.io on December 18, 2023. If updating is not possible, some other mitigations are available. One may disable JS processing by toggling the option `Allow JavaScript Source Fetching` in `Organization Settings > Security & Privacy` and/or disable all untrusted public repositories under `Project Settings > Debug Files`. Alternatively, if JavaScript and native symbolication are not required, disable Symbolicator completely in `config.yml`.
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Analysis
by VulDB Data Team • 12/23/2023
The vulnerability identified as CVE-2023-51451 affects Symbolicator, a critical component of the Sentry error tracking platform that processes and symbolicates stack traces from applications. This service acts as a bridge between application crash reports and human-readable debugging information, making it a valuable target for attackers seeking to exploit internal network resources. The flaw exists in Symbolicator versions 0.3.3 through 2.12.0, where an improperly handled protocol specification allows malicious actors to construct HTTP GET requests that can reach internal network addresses. This represents a classic server-side request forgery vulnerability that enables unauthorized access to internal systems through the Symbolicator service.
The technical exploitation occurs when an attacker crafts a request using an invalid protocol specification that causes Symbolicator to attempt HTTP GET requests to arbitrary URLs, including those containing internal IP addresses. This vulnerability stems from insufficient input validation and protocol handling within the Symbolicator service, allowing attackers to bypass normal network security controls and potentially access internal services that would otherwise be protected by firewalls or network segmentation. The issue manifests through Symbolicator's API, which can expose the responses from these internal requests, creating a data leakage scenario where sensitive internal information becomes accessible through the Sentry platform.
The operational impact of this vulnerability is significant for organizations using self-hosted Sentry instances, as it allows authenticated attackers with registered accounts to potentially access internal network resources through the Symbolicator service. This creates a vector for reconnaissance and further attacks, as attackers can probe internal systems and potentially discover sensitive information about network topology, internal services, and system configurations. The vulnerability affects both the Sentry API and user interface, meaning that even without direct API access, attackers could potentially extract information through the web interface. The risk is particularly concerning in environments where internal systems are not adequately protected or segmented from the network where Symbolicator resides.
The vulnerability has been addressed through multiple release versions including Symbolicator 23.12.1, Sentry self-hosted 23.12.1, and the mitigation was deployed on sentry.io on December 18, 2023. Organizations unable to immediately upgrade can implement several mitigations to reduce risk. The primary defense involves disabling JavaScript processing through the `Allow JavaScript Source Fetching` toggle in organization security settings, which prevents Symbolicator from fetching external JavaScript sources that could be exploited. Additionally, disabling untrusted public repositories under project debug file settings helps prevent access to potentially malicious sources. When full symbolication capabilities are not required, complete disabling of Symbolicator through configuration files provides the strongest protection against this class of attack. This vulnerability aligns with CWE-918, which describes server-side request forgery, and represents a clear example of how improperly validated user input can create dangerous pathways through network security controls. The attack pattern follows ATT&CK technique T1071.004 for application layer protocol, where attackers leverage legitimate application functionality to access unintended network resources, demonstrating the importance of validating all user-supplied data and implementing proper network segmentation controls to prevent lateral movement within internal networks.