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    CVE-2021-1501

    A vulnerability in the SIP inspection engine of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a denial of service (DoS) condition.The vulnerability is due to a crash that occurs during a hash lookup for a SIP pinhole connection. An attacker could exploit this vulnerability by sending crafted SIP traffic through an affected device. A successful exploit could allow the attacker to cause a crash and reload of the affected device.

    Published:Apr 29, 2021
    Last Modified:Aug 11, 2026
    EPS:Apr 29, 2021
    EPSS Score:0.01341
    CVSS Score:8.6

    Affected Products

    Vendor
    Cisco
    Product
    Adaptive Security Appliance Software
    Vendor
    Cisco
    Product
    Secure Firewall Threat Defense

    Exploits

    No exploit reference

    Common Weakness Enumeration

    CWE-613 Insufficient Session Expiration

    Common Attack Pattern Enumeration and Classification (CAPEC)

    No CAPEC recorded yet

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    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High