CVE-2023-4806

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ModerateModerate ImpactWhat does this mean?

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Description

A flaw was found in glibc. In an extremely rare situation, the getaddrinfo function may access memory that has been freed, resulting in an application crash. This issue is only exploitable when a NSS module implements only the _nss_*_gethostbyname2_r and _nss_*_getcanonname_r hooks without implementing the _nss_*_gethostbyname3_r hook. The resolved name should return a large number of IPv6 and IPv4, and the call to the getaddrinfo function should have the AF_INET6 address family with AI_CANONNAME, AI_ALL and AI_V4MAPPED as flags.

A flaw was found in glibc. In an extremely rare situation, the getaddrinfo function may access memory that has been freed, resulting in an application crash. This issue is only exploitable when a NSS module implements only the nss_gethostbyname2_r and nss_getcanonname_r hooks without implementing the nss*_gethostbyname3_r hook. The resolved name should return a large number of IPv6 and IPv4, and the call to the getaddrinfo function should have the AF_INET6 address family with AI_CANONNAME, AI_ALL and AI_V4MAPPED as flags.

Statement

This issue is only exploitable with very specific conditions, as detailed in the description. However, all glibc versions shipped in Red Hat Enterprise Linux are vulnerable to this issue.

This issue is only exploitable with very specific conditions, as detailed in the description. However, all glibc versions shipped in Red Hat Enterprise Linux are vulnerable to this issue.

Additional information

  • Bugzilla 2237782: glibc: potential use-after-free in getaddrinfo()
  • CWE-416: Use After Free
  • FAQ: Frequently asked questions about CVE-2023-4806

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

5.9

5.9

Attack Vector

Network

Network

Attack Complexity

High

High

Privileges Required

None

None

User Interaction

None

None

Scope

Unchanged

Unchanged

Confidentiality Impact

None

None

Integrity Impact

None

None

Availability Impact

High

High

CVSS v3 Vector

Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Acknowledgements

This issue was discovered by Siddhesh Poyarekar (Red Hat).

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

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I have a Red Hat product but it is not in the above list, is it affected?

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My product is listed as "Out of Support Scope". What does this mean?

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