Is CVE-2023-4806 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2023-4806 being exploited in the wild.

How severe is CVE-2023-4806?

Medium severity, with a CVSS score of 5.9, published 18 September 2023.

Which products and versions are affected?

Gnu Glibc 2.34-100.el9 and earlier.

Is there a fix for CVE-2023-4806?

A patch was published on 2023-10-05: Red Hat released security updates for RHEL 9 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2023-4806 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2023-4806?

Check whether you run Gnu Glibc at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2023-4806: GNU glibc use-after-free in getaddrinfo

CVE-2023-4806 · Severity: medium · CVSS 5.9 · Published 2023-09-18

A vulnerability has been found in the core system library (glibc) used by almost all Linux-based applications to translate web addresses into IP addresses. In specific, rare configurations, this flaw can cause an application to crash when it looks up a network address. While difficult to trigger, a successful exploit could lead to a denial-of-service, impacting the availability of critical system services and applications.

Technologies: Gnu Glibc. Vendors: Gnu.

Quick answers

Is CVE-2023-4806 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2023-4806 being exploited in the wild.
How severe is CVE-2023-4806?: Medium severity, with a CVSS score of 5.9, published 18 September 2023.
Which products and versions are affected?: Gnu Glibc 2.34-100.el9 and earlier.
Is there a fix for CVE-2023-4806?: A patch was published on 2023-10-05: Red Hat released security updates for RHEL 9 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2023-4806 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2023-4806?: Check whether you run Gnu Glibc at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A use-after-free (UAF) vulnerability exists in the glibc 'getaddrinfo' function. The flaw is triggered when a Name Service Switch (NSS) module implements only the '_nss_*_gethostbyname2_r' and '_nss_*_getcanonname_r' hooks, but lacks the '_nss_*_gethostbyname3_r' hook. For an exploit to occur, the resolved name must return a large number of IPv4 and IPv6 addresses, and the 'getaddrinfo' call must use specific flags (AF_INET6 with AI_CANONNAME, AI_ALL, and AI_V4MAPPED). An attacker who can influence DNS responses or name resolution results could potentially trigger this UAF to cause a denial-of-service (crash). Patches are available through major Linux distributions including Red Hat and Fedora.

Affected products

GNU glibc 2.34-100.el9 and earlier
Red Hat Enterprise Linux 9 9.2, 9.4, 9.6

Timeline

2023-09-18: disclosed
2023-10-05: patched: Red Hat released security updates for RHEL 9

References

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