It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2022-2022-039 advisory.

    Amazon Linux has been made aware of a potential Branch Target Injection (BTI) issue (sometimes referred to     as Spectre variant 2). This is a known cross-domain transient execution attack where a third party may     seek to cause a disclosure gadget to be speculatively executed after an indirect branch prediction.
    Generally, actors who attempt transient execution attacks do not have access to the data on the hosts they     attempt to access (e.g. where privilege-level isolation is in place). For such attacks to succeed, actors     need to be able to run code on the (virtual) machine hosting the data in which they are interested.

    To mitigate this issue, Amazon Linux recommends that customers disable unprivileged eBPF.  This     configuration, having the unprivileged eBPF disabled, is the current default for most Linux distributions     and as of this advisory, is also the default for all Amazon Linux kernels.

    Specific mitigations for various CPUs are listed below.

    Intel CPUs:For Intel CPUs, this applies to all instance types that have CPUs with eIBRS support. They     are:*6i* (all sizes), c5d.metal, c5.metal, g4dn.metal, i3en.metal, m5*.metal, r5*.metal

    Vectors outside of unprivileged eBPF are not currently known, and Intel recommends disabling unprivileged     BPF, as mentioned above. However, optionally enabling spectre_v2=eibrs,lfence on Linux kernel command     line on the instance types mentioned above, would provide additional protection.

    AMD CPUs:As part of the investigation triggered by this issue, AMD now recommends using a different     software mitigation inside the Linux kernel, which the Amazon Linux kernel is enabling by default. This     means that the Linux kernel will use the generic retpoline software mitigation, instead of the specialized     AMD one, on AMD instances (*5a*). This is done by default, and no administrator action is needed.

    ARM CPUs:The Amazon Linux kernel now enables, by default, a software mitigation for this issue, on all     ARM-based EC2 instance types.

    Non-transparent sharing of branch predictor selectors between contexts in some Intel(R) Processors may     allow an authorized user to potentially enable information disclosure. (CVE-2022-0001)

    Non-transparent sharing of branch predictor within a context in some Intel(r) Processors may allow an     authorized user to potentially enable information disclosure via local access. (CVE-2022-0002)

    A flaw was found in the way the flags member of the new pipe buffer structure was lacking proper     initialization in copy_page_to_iter_pipe and push_pipe functions in the Linux kernel and could thus     contain stale values. An unprivileged local user could use this flaw to write to pages in the page cache     backed by read only files and as such escalate their privileges on the system. (CVE-2022-0847)References     to CVE-2021-26401, CVE-2021-26341, CVE-2022-23960 and CVE-2022-1055 have been added after the original     release of this advisory, however those vulnerabilities were fixed by the packages referenced by this     advisory's initial release on 2022-03-07

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Detections

Analytics

Amazon Linux 2022 : bpftool, kernel, kernel-devel (ALAS2022-2022-039)

high Nessus Plugin ID 164727

Version 1.5

Version 1.4

Version 1.5 Dec 12, 2024, 9:55 AM CVSS metrics ("Cvssv4 score" set to 8.6) CVSS metrics ("Cvssv4 threat vector" set to "CVSS:4.0/E:A") CVSS metrics ("Cvssv4 vector" set to "CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N") Detection (updated detection logic) Plugin metadata Plugin Feed: 202412120955
Version 1.4 Jan 13, 2023, 4:18 PM Exploit attributes ("Exploit framework core" set to "True") Plugin Feed: 202301131618