CVE-2019-10639

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    CVE-2019-10639

    Published: 5 Jul 2019Last Modified: 15 Mar 2026

    Summary:

    Details: The Linux kernel 4.x (starting from 4.1) and 5.x before 5.0.8 allows Information Exposure (partial kernel address disclosure), leading to a KASLR bypass. Specifically, it is possible to extract the KASLR kernel image offset using the IP ID values the kernel produces for connection-less protocols (e.g., UDP and ICMP). When such traffic is sent to multiple destination IP addresses, it is possible to obtain hash collisions (of indices to the counter array) and thereby obtain the hashing key (via enumeration). This key contains enough bits from a kernel address (of a static variable) so when the key is extracted (via enumeration), the offset of the kernel image is exposed. This attack can be carried out remotely, by the attacker forcing the target device to send UDP or ICMP (or certain other) traffic to attacker-controlled IP addresses. Forcing a server to send UDP traffic is trivial if the server is a DNS server. ICMP traffic is trivial if the server answers ICMP Echo requests (ping). For client targets, if the target visits the attacker's web page, then WebRTC or gQUIC can be used to force UDP traffic to attacker-controlled IP addresses. NOTE: this attack against KASLR became viable in 4.1 because IP ID generation was changed to have a dependency on an address associated with a network namespace.

    References: http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00014.html, https://lists.debian.org/debian-lts-announce/2019/07/msg00022.html, https://support.f5.com/csp/article/K32804955?utm_source=f5support&amp%3Butm_medium=RSS, https://www.oracle.com/security-alerts/cpuApr2021.html, https://lists.debian.org/debian-lts-announce/2019/08/msg00017.html, https://support.f5.com/csp/article/K32804955, https://usn.ubuntu.com/4118-1/, http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00025.html, https://seclists.org/bugtraq/2019/Aug/18, https://usn.ubuntu.com/4115-1/, https://arxiv.org/pdf/1906.10478.pdf, https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.8, https://security.netapp.com/advisory/ntap-20190806-0001/, https://www.debian.org/security/2019/dsa-4497, https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=355b98553789b646ed97ad801a619ff898471b92, https://github.com/torvalds/linux/commit/355b98553789b646ed97ad801a619ff898471b92

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    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