CVE-2007-4406 in ircu
Summary
by MITRE
ircu 2.10.12.01 through 2.10.12.04 does not remove ops privilege after a join from a server with an older timestamp (TS), which allows remote attackers to gain control of a channel during a split.
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Analysis
by VulDB Data Team • 09/07/2018
The vulnerability described in CVE-2007-4406 affects ircu server software versions 2.10.12.01 through 2.10.12.04 and represents a significant security flaw in the handling of channel operations privileges during network splits. This issue stems from the improper management of timestamp synchronization between server nodes, creating a window where malicious actors can exploit the protocol's design to gain unauthorized control over channels. The vulnerability specifically manifests when a server with an older timestamp rejoins the network, leading to a scenario where the server fails to properly revoke operator privileges from users who previously held them, thereby allowing unauthorized access to channel management functions.
The technical root cause of this vulnerability lies in the ircu protocol implementation's failure to properly validate timestamp information during server synchronization processes. When a network split occurs and servers reconnect with different timestamp values, the system should properly revalidate all channel privileges and operational states. However, in the affected versions, the software incorrectly maintains existing operator privileges even when a server rejoins with an older timestamp, effectively bypassing the normal privilege revocation mechanism that should occur during network reconciliation. This flaw directly relates to CWE-284, which addresses improper access control in software systems, and specifically targets the improper privilege management aspect of access control vulnerabilities.
The operational impact of this vulnerability is severe as it enables remote attackers to execute unauthorized channel takeovers during network instability periods. During a network split, when servers temporarily lose connectivity and then reconnect, the attacker can exploit this timing window to gain operator status on channels without proper authentication. This creates a persistent security risk where malicious actors can manipulate channel content, ban legitimate users, or perform other operator-level actions that compromise the integrity of the IRC network. The vulnerability is particularly dangerous because it can be exploited without requiring direct access to the server or knowledge of user credentials, making it a significant threat to network administrators and users who rely on IRC for communication and collaboration.
Mitigation strategies for this vulnerability require immediate software updates to versions that properly address the timestamp synchronization and privilege revocation mechanisms. Network administrators should ensure that all ircu servers are upgraded to patched versions that correctly handle timestamp comparisons and privilege management during server reconnection scenarios. Additionally, implementing network monitoring to detect unusual timestamp behavior and abnormal privilege changes can help identify exploitation attempts. The ATT&CK framework categorizes this type of vulnerability under privilege escalation techniques, specifically targeting the 'T1068 - Exploitation for Privilege Escalation' tactic. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of such vulnerabilities, while maintaining regular security audits to identify and remediate similar issues in other network infrastructure components.