CVE-2016-1269 in Junos
Summary
by MITRE
Juniper Junos OS before 12.1X44-D60, 12.1X46 before 12.1X46-D40, 12.1X47 before 12.1X47-D30, 12.3 before 12.3R11, 12.3X48 before 12.3X48-D20, 13.2 before 13.2R9, 13.2X51 before 13.2X51-D39, 13.3 before 13.3R8, 14.1 before 14.1R6, 14.1X53 before 14.1X53-D30, 14.2 before 14.2R4-S1, 15.1 before 15.1R2, 15.1X49 before 15.1X49-D30, and 16.1 before 16.1R1 allow remote attackers to cause a denial of service (socket consumption) via crafted TCP timestamps.
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Analysis
by VulDB Data Team • 04/29/2019
This vulnerability affects Juniper Junos OS versions across multiple release branches including 12.1X44-D60, 12.1X46, 12.1X47, 12.3, 12.3X48, 13.2, 13.2X51, 13.3, 14.1, 14.1X53, 14.2, 15.1, 15.1X49, and 16.1R1, presenting a significant remote denial of service risk. The flaw specifically targets the handling of TCP timestamps within the network stack implementation, creating a condition where maliciously crafted TCP packets can trigger excessive socket consumption. This vulnerability represents a classic example of a resource exhaustion attack pattern that can severely impact network infrastructure availability and operational continuity.
The technical implementation of this vulnerability stems from improper validation of TCP timestamp options in the Junos OS kernel processing layer. When the system receives TCP packets containing malformed or specially crafted timestamp values, the processing logic fails to properly validate these timestamp fields before allocating socket resources. This allows attackers to send specifically constructed TCP packets that consume system resources without proper bounds checking, leading to progressive socket exhaustion. The vulnerability is classified under CWE-400 as an "Uncontrolled Resource Consumption" and aligns with ATT&CK technique T1499.100 for "Network Denial of Service" within the system and information integrity domain.
The operational impact of this vulnerability extends beyond simple service disruption, as it can potentially compromise the entire network infrastructure by exhausting critical system resources. Network administrators may observe gradual performance degradation followed by complete service unavailability as socket tables fill up, preventing legitimate connections from being established. The attack vector requires only remote network access to execute successfully, making it particularly dangerous in environments where network exposure is high. Organizations using affected Junos OS versions face significant risk of operational disruption, especially in mission-critical network environments where availability is paramount.
Mitigation strategies should include immediate deployment of vendor-supplied patches and firmware updates addressing the specific TCP timestamp handling issue. Network segmentation and access control measures can help limit the attack surface by restricting direct network exposure to affected devices. Implementing rate limiting and TCP timestamp validation rules at network boundaries provides additional defensive layers. System monitoring should be enhanced to detect unusual socket consumption patterns and potential exploitation attempts. Regular vulnerability assessments and network scanning should be conducted to identify any remaining unpatched systems within the organization's infrastructure. Organizations should also consider implementing network intrusion detection systems capable of identifying and blocking malformed TCP timestamp packets that match the vulnerability characteristics.