Shim: out-of-bounds read printing error messages
Noroxi assessment
Priority: Monitor (action score 22/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.43% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Azure Linux 3.0 ARM 15.8-3; Azure Linux 3.0 x64 15.8-3; CBL Mariner 2.0 ARM 15.8-1.
Low priority for now. Upgrade to Azure Linux 3.0 ARM 15.8-3; Azure Linux 3.0 x64 15.8-3; CBL Mariner 2.0 ARM 15.8-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
A flaw was found in Shim when an error happened while creating a new ESL variable. If Shim fails to create the new variable, it tries to print an error message to the user; however, the number of parameters used by the logging function doesn't match the format string used by it, leading to a crash under certain circumstances.
- Published
- Jan 29, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 37th percentile
- CWE
- CWE-476
Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.5
- CNA · redhat
- 6.2
- 0.7 point gap
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| redhat | shim | cpe:2.3:a:redhat:shim |
| redhat | enterprise linux | cpe:2.3:o:redhat:enterprise_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- fedoraproject fedora39
- redhat enterprise linux8.0
- redhat enterprise linux9.0
- redhat shimbefore 15.8
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
Red Hat Red Hat Enterprise Linux 7
- 0:15.8-3.el7 and laternot affected · rpm
- 0:15.8-1.el7 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8
- 0:15.8-4.el8_9 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.2 Advanced Update Support
- 0:15.8-2.el8_2 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.2 Telecommunications Update Service
- 0:15.8-2.el8_2 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions
- 0:15.8-2.el8_2 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- 0:15.8-2.el8_4 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.4 Telecommunications Update Service
- 0:15.8-2.el8_4 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions
- 0:15.8-2.el8_4 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support
- 0:15.8-2.el8_6 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support
- 0:15.8-2.el8 and laternot affected · rpm
- 0:15.8-2.el8 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 9
- 0:15.8-4.el9_3 and laternot affected · rpm
Red Hat Red Hat Enterprise Linux 9.0 Extended Update Support
- 0:15.8-3.el9 and laternot affected · rpm
- 0:15.8-2.el9 and laternot affected · rpm
- 0:15.8-2.el9 and laternot affected · rpm
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | shim-aa64 | before 15.8-4.el8_9.alma.1 | 15.8-4.el8_9.alma.1 |
| AlmaLinux:8 | shim-ia32 | before 15.8-4.el8_9.alma.1 | 15.8-4.el8_9.alma.1 |
| AlmaLinux:8 | shim-x64 | before 15.8-4.el8_9.alma.1 | 15.8-4.el8_9.alma.1 |
| AlmaLinux:9 | shim-aa64 | before 15.8-4.el9_3.alma.1 | 15.8-4.el9_3.alma.1 |
| AlmaLinux:9 | shim-x64 | before 15.8-4.el9_3.alma.1 | 15.8-4.el9_3.alma.1 |
| Debian:10 | shim | before 15.8-1~deb10u1 | 15.8-1~deb10u1 |
| Debian:12 | shim | before 15.8-1~deb12u1 | 15.8-1~deb12u1 |
| Debian:13 | shim | before 15.8-1 | 15.8-1 |
| openSUSE:Leap Micro 5.3 | shim | before 15.8-150300.4.20.2 | 15.8-150300.4.20.2 |
| Red Hat:enterprise_linux:7::client | mokutil | before 0:15.8-1.el7 | 0:15.8-1.el7 |
| Red Hat:enterprise_linux:7::client | mokutil-debuginfo | before 0:15.8-1.el7 | 0:15.8-1.el7 |
| Red Hat:enterprise_linux:7::client | shim | before 0:15.8-3.el7 | 0:15.8-3.el7 |
| Red Hat:enterprise_linux:7::client | shim-ia32 | before 0:15.8-1.el7 | 0:15.8-1.el7 |
| Red Hat:enterprise_linux:7::client | shim-signed | before 0:15.8-1.el7 | 0:15.8-1.el7 |
| Red Hat:enterprise_linux:7::client | shim-unsigned-ia32 | before 0:15.8-3.el7 | 0:15.8-3.el7 |
| Red Hat:enterprise_linux:7::client | shim-unsigned-x64 | before 0:15.8-3.el7 | 0:15.8-3.el7 |
| Red Hat:enterprise_linux:7::client | shim-x64 | before 0:15.8-1.el7 | 0:15.8-1.el7 |
| Red Hat:enterprise_linux:8::baseos | shim | before 0:15.8-4.el8_9 | 0:15.8-4.el8_9 |
| Red Hat:enterprise_linux:8::baseos | shim-aa64 | before 0:15.8-4.el8_9 | 0:15.8-4.el8_9 |
| Red Hat:enterprise_linux:8::baseos | shim-ia32 | before 0:15.8-4.el8_9 | 0:15.8-4.el8_9 |
| Red Hat:enterprise_linux:8::baseos | shim-x64 | before 0:15.8-4.el8_9 | 0:15.8-4.el8_9 |
| Red Hat:enterprise_linux:9::baseos | shim | before 0:15.8-4.el9_3 | 0:15.8-4.el9_3 |
| Red Hat:enterprise_linux:9::baseos | shim-aa64 | before 0:15.8-4.el9_3 | 0:15.8-4.el9_3 |
| Red Hat:enterprise_linux:9::baseos | shim-x64 | before 0:15.8-4.el9_3 | 0:15.8-4.el9_3 |
+28
Same product
redhat: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-40547Shim: rce in http boot support may lead to secure boot bypass35Monitor
- CVE-2014-3676Heap-based buffer overflow in Shim allows remote attackers to execute arbitrary code via a crafted IPv6 address, related to the "tftp:// DHC32Monitor
- CVE-2022-28737There's a possible overflow in handle_image() when shim tries to load and execute crafted EFI executables31Monitor
Published before and after this one in the same product
- ← EarlierCVE-2014-3677Oct 22, 2014 · Unspecified vulnerability in Shim might allow attackers to execute arbitrary code via a crafted MOK list, which triggers memory corruption.31Monitor
- ← EarlierCVE-2023-40548Jan 29, 2024 · Shim: interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems29Monitor
- Later →CVE-2023-40549Jan 29, 2024 · Shim: out-of-bounds read in verify_buffer_authenticode() malformed pe file22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Azure Linux 3.0 ARM | 15.8-3 · shim | Microsoft (MSRC) |
| Azure Linux 3.0 x64 | 15.8-3 · shim | Microsoft (MSRC) |
| CBL Mariner 2.0 ARM | 15.8-1 · shim | Microsoft (MSRC) |
| CBL Mariner 2.0 x64 | 15.8-1 · shim | Microsoft (MSRC) |
| almalinux:shim-aa64 | 15.8-4.el8_9.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:shim-ia32 | 15.8-4.el8_9.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:shim-x64 | 15.8-4.el8_9.alma.1 · AlmaLinux:8 | Package registry (OSV) |
| debian:shim | 15.8-1~deb12u1 · Debian:12 | Package registry (OSV) |
| opensuse:shim | 15.8-150300.4.20.2 · openSUSE:Leap Micro 5.3 | Package registry (OSV) |
| red hat:mokutil | 0:15.8-1.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:mokutil-debuginfo | 0:15.8-1.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:shim | 0:15.8-2.el8_2 · Red Hat:rhel_aus:8.2::baseos | Package registry (OSV) |
| red hat:shim-aa64 | 0:15.8-3.el9 · Red Hat:rhel_eus:9.0::baseos | Package registry (OSV) |
| red hat:shim-ia32 | 0:15.8-2.el8_2 · Red Hat:rhel_aus:8.2::baseos | Package registry (OSV) |
| red hat:shim-signed | 0:15.8-1.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:shim-unsigned-aarch64 | 0:15.8-2.el9 · Red Hat:rhel_eus:9.0::appstream | Package registry (OSV) |
| red hat:shim-unsigned-ia32 | 0:15.8-3.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:shim-unsigned-x64 | 0:15.8-2.el9 · Red Hat:rhel_eus:9.0::crb | Package registry (OSV) |
| red hat:shim-x64 | 0:15.8-2.el8_2 · Red Hat:rhel_aus:8.2::baseos | Package registry (OSV) |
| suse:pcr-oracle | 0.4.6-2.1 · SUSE:Linux Micro 6.0 | Package registry (OSV) |
| suse:shim | 15.8-150300.4.20.2 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-476 · NULL Pointer DereferenceCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (11 more)Show less
- access.redhat.com/errata/RHSA-2024:1835
- access.redhat.com/errata/RHSA-2024:1873
- access.redhat.com/errata/RHSA-2024:1876
- access.redhat.com/errata/RHSA-2024:1883
- access.redhat.com/errata/RHSA-2024:1902
- access.redhat.com/errata/RHSA-2024:1903
- access.redhat.com/errata/RHSA-2024:1959
- access.redhat.com/errata/RHSA-2024:2086
- access.redhat.com/security/cve/CVE-2023-40546
- bugzilla.redhat.com/show_bug.cgi?id=2241796
- lists.debian.org/debian-lts-announce/2024/05/msg00009.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.