CVE-2023-4911 | Glibc: buffer overflow in ld.so leading to privilege escalation

Exp

A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.

Published: 2023-10-03 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-4911 is rated Critical Active Threat (93.9/100): CVSS High severity, with high exploitation likelihood (EPSS 81.42%, 100th percentile). CISA KEV confirms active exploitation (added 2023-11-21) affecting GNU / GNU C Library. a weakness (CWE-122) Unauthenticated remote administrative access may be possible. EPSS rose +2.82% over the last day, indicating growing attacker interest. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2023-4911

Name: GNU C Library Buffer Overflow Vulnerability · CISA KEV detail

Exploit added: 2023-11-21

Action due: 2023-12-12

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Public exploit references (Exploit-DB) for CVE-2023-4911

EDB-ID Source Kind Published Link
52479 exploit_db edb 2026-02-11 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
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Exploit prediction scoring system (EPSS) score for CVE-2023-4911

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-28 78.61% 81.42% +2.82%
2 2026-06-15 65.05% 78.61% +13.56%
3 2026-06-09 — 65.05% —

Full EPSS history (133 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-4911

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2023-4911

GitHub Security Advisory for CVE-2023-4911

GHSA-m77w-6vjw-wh2f · Severity: high — A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the...

OS Trackers for CVE-2023-4911

vendor priority summary link
debian not yet assigned CVE-2023-4911 not yet assigned priority: Debian including 1 source packages (glibc), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-4911
gentoo high CVE-2023-4911: 1 GLSA(s) (202310-03), 1 atom(s) (sys-libs/glibc); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-4911
redhat high — https://access.redhat.com/security/cve/CVE-2023-4911
suse high CVE-2023-4911 severity important: SUSE including 514 source package names (compat-libpthread-nonshared-2.28-225.el8_8.6, glibc, …), 855 product×package rows across 51 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 7.1, … (51 product lines)): Fixed 496, Known Not Affected 359. https://www.suse.com/security/cve/CVE-2023-4911/
ubuntu high CVE-2023-4911 high priority: Ubuntu including 2 source packages (eglibc, glibc), 18 status rows across 9 suites (bionic, focal, jammy, lunar, mantic, noble, trusty, upstream, xenial): DNE 7, not-affected 4, released 4, needs-triage 2, ignored 1. https://ubuntu.com/security/CVE-2023-4911

Affected software / configurations for CVE-2023-4911

Vendor Product Version Raw CPE
netapp bootstrap_os — cpe:2.3:o:netapp:bootstrap_os:-:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware >= 3.1.5 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_cpu_1518f-4_pn\/dp_mfp_firmware >= 3.1.5 cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518f-4_pn\/dp_mfp_firmware:*:*:*:*:*:*:*:*
siemens siplus_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware >= 3.1.5 cpe:2.3:o:siemens:siplus_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware:*:*:*:*:*:*:*:*
siemens simatic_s7-1500_tm_mfp_firmware < 1.1 cpe:2.3:o:siemens:simatic_s7-1500_tm_mfp_firmware:*:*:*:*:*:*:*:*
gnu glibc >= 2.34, < 2.39 cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*
fedoraproject fedora 37 cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*
fedoraproject fedora 39 cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*
redhat codeready_linux_builder 9.0 cpe:2.3:a:redhat:codeready_linux_builder:9.0:*:*:*:*:*:*:*
redhat codeready_linux_builder_eus 8.6 cpe:2.3:a:redhat:codeready_linux_builder_eus:8.6:*:*:*:*:*:*:*
redhat codeready_linux_builder_eus 9.2 cpe:2.3:a:redhat:codeready_linux_builder_eus:9.2:*:*:*:*:*:*:*
redhat codeready_linux_builder_eus 9.4 cpe:2.3:a:redhat:codeready_linux_builder_eus:9.4:*:*:*:*:*:*:*
redhat codeready_linux_builder_eus 9.6 cpe:2.3:a:redhat:codeready_linux_builder_eus:9.6:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_arm64 9.0_aarch64 cpe:2.3:a:redhat:codeready_linux_builder_for_arm64:9.0_aarch64:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_arm64_eus 8.6 cpe:2.3:a:redhat:codeready_linux_builder_for_arm64_eus:8.6:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_arm64_eus 9.2_aarch64 cpe:2.3:a:redhat:codeready_linux_builder_for_arm64_eus:9.2_aarch64:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_arm64_eus 9.4_aarch64 cpe:2.3:a:redhat:codeready_linux_builder_for_arm64_eus:9.4_aarch64:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_arm64_eus 9.6_aarch64 cpe:2.3:a:redhat:codeready_linux_builder_for_arm64_eus:9.6_aarch64:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_ibm_z_systems 9.0_s390x cpe:2.3:a:redhat:codeready_linux_builder_for_ibm_z_systems:9.0_s390x:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_ibm_z_systems_eus 8.6 cpe:2.3:a:redhat:codeready_linux_builder_for_ibm_z_systems_eus:8.6:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_ibm_z_systems_eus 9.2_s390x cpe:2.3:a:redhat:codeready_linux_builder_for_ibm_z_systems_eus:9.2_s390x:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_ibm_z_systems_eus 9.4_s390x cpe:2.3:a:redhat:codeready_linux_builder_for_ibm_z_systems_eus:9.4_s390x:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_ibm_z_systems_eus 9.6_s390x cpe:2.3:a:redhat:codeready_linux_builder_for_ibm_z_systems_eus:9.6_s390x:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_power_little_endian 9.0_ppc64le cpe:2.3:a:redhat:codeready_linux_builder_for_power_little_endian:9.0_ppc64le:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_power_little_endian_eus 8.6 cpe:2.3:a:redhat:codeready_linux_builder_for_power_little_endian_eus:8.6:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_power_little_endian_eus 9.2_ppc64le cpe:2.3:a:redhat:codeready_linux_builder_for_power_little_endian_eus:9.2_ppc64le:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_power_little_endian_eus 9.4_ppc64le cpe:2.3:a:redhat:codeready_linux_builder_for_power_little_endian_eus:9.4_ppc64le:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_power_little_endian_eus 9.6_ppc64le cpe:2.3:a:redhat:codeready_linux_builder_for_power_little_endian_eus:9.6_ppc64le:*:*:*:*:*:*:*
redhat virtualization 4.0 cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:*
redhat virtualization_host 4.0 cpe:2.3:a:redhat:virtualization_host:4.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.6 cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_eus 9.2 cpe:2.3:o:redhat:enterprise_linux_eus:9.2:*:*:*:*:*:*:*
redhat enterprise_linux_eus 9.4 cpe:2.3:o:redhat:enterprise_linux_eus:9.4:*:*:*:*:*:*:*
redhat enterprise_linux_eus 9.6 cpe:2.3:o:redhat:enterprise_linux_eus:9.6:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64 9.0_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64:9.0_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 8.6_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:8.6_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 9.2_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:9.2_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 9.4_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:9.4_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 9.6_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:9.6_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems 9.0_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:9.0_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 9.2_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:9.2_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 9.4_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:9.4_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 9.6_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:9.6_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus_s390x 8.6 cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus_s390x:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_big_endian_eus 8.6_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_big_endian_eus:8.6_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian 9.0_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:9.0_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 9.2_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.2_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 9.4_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.4_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 9.6_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.6_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 9.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:9.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 9.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:9.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 9.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:9.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 9.2_ppc64le cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.2_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 9.4_ppc64le cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.4_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 9.6_ppc64le cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.6_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 8.6 cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_update_services_for_sap_solutions 9.2 cpe:2.3:o:redhat:enterprise_linux_update_services_for_sap_solutions:9.2:*:*:*:*:*:*:*
redhat enterprise_linux_update_services_for_sap_solutions 9.4 cpe:2.3:o:redhat:enterprise_linux_update_services_for_sap_solutions:9.4:*:*:*:*:*:*:*
redhat enterprise_linux_update_services_for_sap_solutions 9.6 cpe:2.3:o:redhat:enterprise_linux_update_services_for_sap_solutions:9.6:*:*:*:*:*:*:*
canonical ubuntu_linux 22.04 cpe:2.3:o:canonical:ubuntu_linux:22.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 23.04 cpe:2.3:o:canonical:ubuntu_linux:23.04:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
debian debian_linux 12.0 cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*
netapp h410c_firmware — cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:*
netapp h300s_firmware — cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:*
netapp h500s_firmware — cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:*
netapp h700s_firmware — cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:*
netapp h410s_firmware — cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:*
netapp ontap_select_deploy_administration_utility — cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*

References for CVE-2023-4911

URL Tags
https://access.redhat.com/errata/RHSA-2023:5453 Third Party Advisory
https://access.redhat.com/errata/RHSA-2023:5454 Third Party Advisory
https://access.redhat.com/errata/RHSA-2023:5455 Third Party Advisory
https://access.redhat.com/errata/RHSA-2023:5476 Third Party Advisory
https://access.redhat.com/errata/RHSA-2024:0033 Third Party Advisory
https://access.redhat.com/security/cve/CVE-2023-4911 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2238352 Issue Tracking Patch
https://www.qualys.com/2023/10/03/cve-2023-4911/looney-tunables-local-privilege-escalation-glibc-ld-so.txt Exploit Third Party Advisory
https://www.qualys.com/cve-2023-4911/ Third Party Advisory
http://packetstormsecurity.com/files/174986/glibc-ld.so-Local-Privilege-Escalation.html Exploit Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/176288/Glibc-Tunables-Privilege-Escalation.html Exploit Third Party Advisory VDB Entry
http://seclists.org/fulldisclosure/2023/Oct/11 Exploit Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/10/03/2 Exploit Mailing List
http://www.openwall.com/lists/oss-security/2023/10/03/3 Mailing List
http://www.openwall.com/lists/oss-security/2023/10/05/1 Mailing List
http://www.openwall.com/lists/oss-security/2023/10/13/11 Mailing List
http://www.openwall.com/lists/oss-security/2023/10/14/3 Mailing List
http://www.openwall.com/lists/oss-security/2023/10/14/5 Mailing List
http://www.openwall.com/lists/oss-security/2023/10/14/6 Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/4DBUQRRPB47TC3NJOUIBVWUGFHBJAFDL/ Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/DFG4P76UHHZEWQ26FWBXG76N2QLKKPZA/ Mailing List
https://lists.fedoraproject.org/archives/list/[email protected]/message/NDAQWHTSVOCOZ5K6KPIWKRT3JX4RTZUR/ Mailing List
https://security.gentoo.org/glsa/202310-03 Third Party Advisory
https://security.netapp.com/advisory/ntap-20231013-0006/ Third Party Advisory
https://www.debian.org/security/2023/dsa-5514 Mailing List
https://www.exploit-db.com/exploits/52479 Exploit Third Party Advisory VDB Entry
https://cert-portal.siemens.com/productcert/html/ssa-082556.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-794697.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-831302.html Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4911 US Government Resource
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