A flaw was found in glibc. The realpath() function can mistakenly return an unexpected value, potentially leading to information leakage and disclosure of sensitive data.

The remote host is affected by the vulnerability described in GLSA-202208-24 (GNU C Library: Multiple Vulnerabilities)

  - The wordexp function in the GNU C Library (aka glibc) through 2.33 may crash or read arbitrary memory in     parse_param (in posix/wordexp.c) when called with an untrusted, crafted pattern, potentially resulting in     a denial of service or disclosure of information. This occurs because atoi was used but strtoul should     have been used to ensure correct calculations. (CVE-2021-35942)

  - In librt in the GNU C Library (aka glibc) through 2.34, sysdeps/unix/sysv/linux/mq_notify.c mishandles     certain NOTIFY_REMOVED data, leading to a NULL pointer dereference. NOTE: this vulnerability was     introduced as a side effect of the CVE-2021-33574 fix. (CVE-2021-38604)

  - The deprecated compatibility function svcunix_create in the sunrpc module of the GNU C Library (aka glibc)     through 2.34 copies its path argument on the stack without validating its length, which may result in a     buffer overflow, potentially resulting in a denial of service or (if an application is not built with a     stack protector enabled) arbitrary code execution. (CVE-2022-23218)

  - The deprecated compatibility function clnt_create in the sunrpc module of the GNU C Library (aka glibc)     through 2.34 copies its hostname argument on the stack without validating its length, which may result in     a buffer overflow, potentially resulting in a denial of service or (if an application is not built with a     stack protector enabled) arbitrary code execution. (CVE-2022-23219)

  -  Please review the referenced CVE identifiers for details.  (CVE-2021-3998)

  - glibc: Off-by-one buffer overflow/underflow in getcwd() (CVE-2021-3999)

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

The remote Ubuntu 18.04 LTS / 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-5310-1 advisory.

    Jan Engelhardt, Tavis Ormandy, and others discovered that the GNU C Library iconv feature incorrectly     handled certain input sequences. An attacker could possibly use this issue to cause the GNU C Library to     hang or crash, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu     20.04 LTS. (CVE-2016-10228, CVE-2019-25013, CVE-2020-27618, CVE-2020-29562, CVE-2021-3326)

    Jason Royes and Samuel Dytrych discovered that the GNU C Library incorrectly handled signed comparisons on     ARMv7 targets. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a     denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS and     Ubuntu 20.04 LTS. (CVE-2020-6096)

    It was discovered that the GNU C Library nscd daemon incorrectly handled certain netgroup lookups. An     attacker could possibly use this issue to cause the GNU C Library to crash, resulting in a denial of     service. This issue only affected Ubuntu 20.04 LTS. (CVE-2021-27645)

    It was discovered that the GNU C Library wordexp function incorrectly handled certain patterns. An     attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or     possibly obtain sensitive information. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.
    (CVE-2021-35942)

    It was discovered that the GNU C Library realpath function incorrectly handled return values. An attacker     could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 21.10.
    (CVE-2021-3998)

    It was discovered that the GNU C library getcwd function incorrectly handled buffers. An attacker could     use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute     arbitrary code. (CVE-2021-3999)

    It was discovered that the GNU C Library sunrpc module incorrectly handled buffer lengths. An attacker     could possibly use this issue to cause the GNU C Library to crash, resulting in a denial of service.
    (CVE-2022-23218, CVE-2022-23219)

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

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

ID	Name	Product	Family	Severity
164108	GLSA-202208-24 : GNU C Library: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	critical
158502	Ubuntu 18.04 LTS / 20.04 LTS : GNU C Library vulnerabilities (USN-5310-1)	Nessus	Ubuntu Local Security Checks	critical

Detections

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CVE-2021-3998

high

Tenable Plugins

critical

critical