# CVE-2023-4527: Glibc: stack read overflow in getaddrinfo in no-aaaa mode

Status: published. Published: 2023-09-18. Updated: 2026-11-07.

A flaw was found in glibc. When the getaddrinfo function is called with the AF_UNSPEC address family and the system is configured with no-aaaa mode via /etc/resolv.conf, a DNS response via TCP larger than 2048 bytes can potentially disclose stack contents through the function returned address data, and may cause a crash.

## Remediation

- workaround: Removing the no-aaaa diagnostic option from /etc/resolv.conf will mitigate this flaw. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 8 (glibc): ≥ 0:2.28-225.el8_8.6; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (glibc): ≥ 0:2.34-60.el9_2.7; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (compat-glibc): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (glibc): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (compat-glibc): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (glibc): Version range not reported. Source: CNA: redhat
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP

## Severity and prioritization

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 1.67% as of 2026-11-07; percentile 76.92%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-121

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2023:5453 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2023:5455 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2023-4527 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2234712 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- http://www.openwall.com/lists/oss-security/2023/09/25/1 (ADP: CVE; x_transferred)

- https://access.redhat.com/errata/RHSA-2023:5453 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred)

- https://access.redhat.com/errata/RHSA-2023:5455 (ADP: CVE; vendor-advisory, x_refsource_REDHAT, x_transferred)

- https://access.redhat.com/security/cve/CVE-2023-4527 (ADP: CVE; vdb-entry, x_refsource_REDHAT, x_transferred)

- https://bugzilla.redhat.com/show_bug.cgi?id=2234712 (ADP: CVE; issue-tracking, x_refsource_REDHAT, x_transferred)

- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4DBUQRRPB47TC3NJOUIBVWUGFHBJAFDL/ (ADP: CVE; x_transferred)

- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DFG4P76UHHZEWQ26FWBXG76N2QLKKPZA/ (ADP: CVE; x_transferred)

- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NDAQWHTSVOCOZ5K6KPIWKRT3JX4RTZUR/ (ADP: CVE; x_transferred)

- https://security.gentoo.org/glsa/202310-03 (ADP: CVE; x_transferred)

- https://security.netapp.com/advisory/ntap-20231116-0012/ (ADP: CVE; x_transferred)

- https://cert-portal.siemens.com/productcert/html/ssa-831302.html (ADP: siemens-SADP)

- https://cert-portal.siemens.com/productcert/html/ssa-082556.html (ADP: siemens-SADP)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2023-4527; retrieved 2026-11-07; source updated 2026-11-07

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2023-4527; retrieved 2026-11-07; source updated Not reported

Revision: 8b0a7bc4653fa89b58dce1fd7df74a5c96d7e52dcdf00a20754c659b70cfdee5

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