CVE-2023-4911
Looney Tunables
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.
- CVSS
- 7.8Highscored by the publisher (CNA)
- Exploited in the wild
- Yes, in CISA KEV since 21 Nov 2023CISA deadline for US federal agencies: 12 Dec 2023public exploit code
- EPSS
- 63.8%chance of exploitation in the next 30 daystop 0.8% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 3 Oct 2023analysed here 12 Nov 2026
Do first. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. (CISA's required action for this KEV entry)
Summary
Triage
- Attack surface
- Server-side
- Exploitable
- At runtime
- Attack vector
- local
- Can a WAF block it?
- No. See why
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
Products named in our analysis
- netapp:bootstrap_os
- siemens:simatic_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware
- siemens:simatic_s7-1500_cpu_1518f-4_pn\/dp_mfp_firmware
- siemens:siplus_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware
- siemens:simatic_s7-1500_tm_mfp_firmware
- gnu:glibc
- fedoraproject:fedora
- redhat:codeready_linux_builder
- redhat:codeready_linux_builder_eus
- redhat:codeready_linux_builder_for_arm64
- redhat:codeready_linux_builder_for_arm64_eus
- redhat:codeready_linux_builder_for_ibm_z_systems
- redhat:codeready_linux_builder_for_ibm_z_systems_eus
- redhat:codeready_linux_builder_for_power_little_endian
- redhat:codeready_linux_builder_for_power_little_endian_eus
- redhat:virtualization
- redhat:virtualization_host
- redhat:enterprise_linux
- redhat:enterprise_linux_eus
- redhat:enterprise_linux_for_arm_64
- redhat:enterprise_linux_for_arm_64_eus
- redhat:enterprise_linux_for_ibm_z_systems
- redhat:enterprise_linux_for_ibm_z_systems_eus
- redhat:enterprise_linux_for_ibm_z_systems_eus_s390x
- redhat:enterprise_linux_for_power_big_endian_eus
- redhat:enterprise_linux_for_power_little_endian
- redhat:enterprise_linux_for_power_little_endian_eus
- redhat:enterprise_linux_server_aus
- redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions
- redhat:enterprise_linux_server_tus
Fix and mitigation
WAF and other mitigations
Can a WAF block it? No. The attack needs local access to the machine, so a WAF is not on its path.
Also consider: patch
Based on the attack vector (local or physical access). We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 21 Nov 2023.
- CISA due date
- 12 Dec 2023, the remediation deadline for US federal agencies
- CISA required action
- Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Public exploit code
- Yes: 1 on Exploit-DB · 1 Metasploit module · 22 GitHub proofs of concept
- CISA SSVC
- exploitation active, automatable no, technical impact totalAssessed by CISA 15 Oct 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Exploit-DB
- glibc 2.38 - Buffer Overflowlocal, 11 Feb 2026
Metasploit
- exploit/linux/local/glibc_tunables_priv_escexploit, rank excellent
GitHub proofs of concept
- leesh3288/CVE-2023-4911394 stars
- RickdeJager/CVE-2023-4911167 stars
- chaudharyarjun/LooneyPwner43 stars
- hadrian3689/looney-tunables-CVE-2023-491129 stars
and 18 more repositories
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 3 Oct 2023Published
- 4 Oct 2023First public exploit or proof of conceptsame day later
- 21 Nov 2023Added to CISA KEV (exploited in the wild)48 days later
- 12 Dec 2023CISA remediation due date (US federal agencies)21 days later
- 15 Oct 2025CISA SSVC assessment: exploitation active674 days (about 2 years) later
- 7 Nov 2026CVE record last updated388 days (about 1 year) later
- 12 Nov 2026Analysed by vulneraibility.com5 days later
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Metric | Value | What it means |
|---|---|---|
| Attack vector | LocalLocal access required (shell, logged-in user). | Local access required (shell, logged-in user). |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | LowThe attacker needs basic user privileges. | The attacker needs basic user privileges. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | HighFull outage possible. | Full outage possible. |
Common questions
Is CVE-2023-4911 being exploited?
Yes. CVE-2023-4911 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2023-4911?
CVE-2023-4911 is rated High with a CVSS score of 7.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2023-4911?
Yes. A fix has been recorded for CVE-2023-4911. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2023-4911 affect?
CVE-2023-4911 affects netapp:bootstrap_os, siemens:simatic_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware, siemens:simatic_s7-1500_cpu_1518f-4_pn\/dp_mfp_firmware, siemens:siplus_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware, and 26 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
30 references in the CVE record, grouped by the tags the record gives them.
Advisories (5)
- access.redhat.com /errata/RHSA-2023:5453
- access.redhat.com /errata/RHSA-2023:5454
- access.redhat.com /errata/RHSA-2023:5455
- access.redhat.com /errata/RHSA-2023:5476
- access.redhat.com /errata/RHSA-2024:0033
Other links (25)
- access.redhat.com /security/cve/CVE-2023-4911
- bugzilla.redhat.com /show_bug.cgi?id=2238352
- qualys.com /2023/10/03/cve-2023-4911/looney-tunables-local-privilege-escalation-glibc-ld-so
- qualys.com /cve-2023-4911/
- exploit-db.com /exploits/52479
- packetstormsecurity.com /files/174986/glibc-ld.so-Local-Privilege-Escalation.html
Show 19 more
- packetstormsecurity.com /files/176288/Glibc-Tunables-Privilege-Escalation.html
- seclists.org /fulldisclosure/2023/Oct/11
- openwall.com /lists/oss-security/2023/10/03/2
- openwall.com /lists/oss-security/2023/10/03/3
- openwall.com /lists/oss-security/2023/10/05/1
- openwall.com /lists/oss-security/2023/10/13/11
- openwall.com /lists/oss-security/2023/10/14/3
- openwall.com /lists/oss-security/2023/10/14/5
- openwall.com /lists/oss-security/2023/10/14/6
- lists.fedoraproject.org /archives/list/[email protected]/message/4DBUQRRPB47TC3NJ
- lists.fedoraproject.org /archives/list/[email protected]/message/DFG4P76UHHZEWQ26
- lists.fedoraproject.org /archives/list/[email protected]/message/NDAQWHTSVOCOZ5K6
- security.gentoo.org /glsa/202310-03
- security.netapp.com /advisory/ntap-20231013-0006/
- debian.org /security/2023/dsa-5514
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4911
- cert-portal.siemens.com /productcert/html/ssa-831302.html
- cert-portal.siemens.com /productcert/html/ssa-794697.html
- cert-portal.siemens.com /productcert/html/ssa-082556.html
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Exploit-DB: published exploits
- Metasploit Framework: exploit and scanner modules
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
Similar CVEs
Get CVEs like this by email. Join the free digest: the CVEs we flag as major, all CVSS 8.0 or higher, in up to three emails a day (sent at 05:00, 11:00 and 15:00 UTC). Matching alerts to the products you run needs an account, and accounts are invite-only during the beta.