CVE-2009-3617 in aria2
Summary
by MITRE
Format string vulnerability in the AbstractCommand::onAbort function in src/AbstractCommand.cc in aria2 before 1.6.2, when logging is enabled, allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via format string specifiers in a download URI. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 08/24/2021
The CVE-2009-3617 vulnerability represents a critical format string vulnerability within the aria2 download manager software, specifically affecting versions prior to 1.6.2. This flaw exists within the AbstractCommand::onAbort function located in the src/AbstractCommand.cc source file, creating a dangerous condition where remote attackers can manipulate the application's behavior through carefully crafted input. The vulnerability becomes exploitable when logging functionality is enabled, making it particularly concerning for systems where detailed logging is configured as part of normal operations. The attack vector involves supplying format string specifiers within a download URI, which then gets processed by the vulnerable function, potentially leading to arbitrary code execution or system instability.
The technical nature of this vulnerability stems from improper input validation and handling of user-supplied data within the logging subsystem. When aria2 processes a download URI containing malicious format specifiers, the AbstractCommand::onAbort function fails to properly sanitize or escape these inputs before using them in logging operations. This creates a classic format string vulnerability where attacker-controlled data is interpreted as format specifiers rather than literal text, allowing for memory read/write operations and potential code execution. The CWE-134 classification applies here, as the vulnerability involves the use of a format string with variable arguments where the format string itself comes from an untrusted source. This weakness enables attackers to perform sophisticated attacks including stack smashing, information disclosure, and arbitrary code execution by manipulating the format string parameters.
The operational impact of this vulnerability extends beyond simple denial of service to encompass full system compromise potential. Remote attackers can leverage this flaw to execute arbitrary code with the privileges of the aria2 process, potentially leading to complete system takeover if the application runs with elevated permissions. The vulnerability can also be used to cause application crashes and denial of service conditions, disrupting legitimate download operations and potentially affecting availability. In environments where aria2 is used for automated downloads or integrated into larger systems, this vulnerability could provide attackers with a persistent entry point for further exploitation. The attack requires minimal privileges and can be executed through standard web-based download mechanisms, making it particularly dangerous in public-facing applications or services that utilize aria2 for content delivery.
Mitigation strategies for CVE-2009-3617 focus primarily on immediate software updates to version 1.6.2 or later, where the vulnerability has been patched. Organizations should also implement network-level restrictions to prevent untrusted users from submitting malicious URIs to aria2 instances, particularly in shared or public environments. Additionally, disabling logging functionality when it's not strictly required can reduce the attack surface, though this may impact operational monitoring capabilities. Security teams should monitor for exploitation attempts and implement proper input validation at all levels of the application stack. The ATT&CK framework categorizes this vulnerability under T1059.007 for command and scripting interpreter and T1499.004 for network denial of service, reflecting both the execution and availability impacts. Regular security assessments and vulnerability scanning should include checks for outdated aria2 installations to prevent exploitation of this and similar legacy vulnerabilities that may remain unpatched in production environments.