CVE-2017-17066 in i2pd
Summary
by MITRE
The (1) i2pd before 2.17 and (2) kovri pre-alpha implementations of the I2P routing protocol do not properly handle Garlic DeliveryTypeTunnel packets, which allows remote attackers to obtain sensitive information from process memory via crafted packets that trigger a buffer over-read, as demonstrated by reading sensitive router memory, aka the GarlicRust bug.
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Analysis
by VulDB Data Team • 12/12/2019
The vulnerability identified as CVE-2017-17066 affects implementations of the I2P routing protocol, specifically targeting versions of i2pd before 2.17 and kovri pre-alpha software. This security flaw resides in the handling of Garlic DeliveryTypeTunnel packets within the I2P network infrastructure, representing a critical weakness that undermines the confidentiality and integrity of the anonymous communication system. The vulnerability stems from improper memory management during packet processing, creating opportunities for attackers to extract sensitive information from process memory through carefully crafted malicious packets.
The technical flaw manifests as a buffer over-read condition that occurs when the affected implementations process Garlic DeliveryTypeTunnel packets. This type of memory corruption vulnerability falls under the CWE-121 category of Stack-based Buffer Overflow, though the specific implementation details suggest a more complex memory handling issue that could involve heap-based or other memory access patterns. The vulnerability is particularly dangerous because it allows remote attackers to read arbitrary memory locations, potentially exposing sensitive data including cryptographic keys, session information, or other confidential routing data that should remain protected within the process memory space.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally compromises the security model of the I2P network. When attackers can read process memory through crafted packets, they gain access to router configurations, cryptographic material, and potentially other sensitive information that could be used to compromise the anonymity of the network participants or to launch further attacks against the I2P infrastructure. This vulnerability directly violates the fundamental security principles of the I2P protocol, which relies on secure communication channels to protect user privacy and network integrity. The attack vector is particularly concerning because it requires only remote packet delivery, making it accessible to adversaries who can interact with the network without requiring physical access to the systems.
The attack technique aligns with ATT&CK tactics related to credential access and defense evasion, as demonstrated by the potential for extracting sensitive information from memory. The vulnerability's exploitation could enable adversaries to gather intelligence about network topology, router configurations, or cryptographic keys that would otherwise remain confidential within the I2P network. Mitigation strategies should include immediate updates to affected implementations, implementing proper bounds checking on packet processing, and deploying network monitoring to detect anomalous packet patterns that might indicate exploitation attempts. Additionally, organizations should consider implementing memory protection mechanisms such as stack canaries or address space layout randomization to reduce the effectiveness of potential exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper memory management in network security protocols, particularly in systems designed to protect user privacy and anonymity.