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Inadequate Encryption Strength Affecting kernel-headers package, versions <0:3.10.0-1127.el7

Severity

 Recommended
medium

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.4% (75th percentile)

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  • Snyk IDSNYK-ORACLE7-KERNELHEADERS-2547617
  • published10 Apr 2022
  • disclosed5 Jul 2019
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Introduced: 5 Jul 2019

CVE-2019-10639  (opens in a new tab)
CWE-326  (opens in a new tab)
First added by Snyk

How to fix?

Upgrade Oracle:7 kernel-headers to version 0:3.10.0-1127.el7 or higher.
This issue was patched in ELSA-2020-1016.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-headers package and not the kernel-headers package as distributed by Oracle. See How to fix? for Oracle:7 relevant fixed versions and status.

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