CVE-2023-40548
Shim: interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems
No known exploitation. EPSS puts it in the 35th percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
A buffer overflow was found in Shim in the 32-bit system. The overflow happens due to an addition operation involving a user-controlled value parsed from the PE binary being used by Shim. This value is further used for memory allocation operations, leading to a heap-based buffer overflow. This flaw causes memory corruption and can lead to a crash or data integrity issues during the boot phase.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.4% chance of exploitation activity in the next 30 days, which ranks it in the 35th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
7 events over 879 days, from the signal feeds we watch.
- Patch availableworkaround available, record updated
- OpenVAS check added
- Publishedweakness classified, att&ck mapped
Affected products
- shimOperating Systems / linux-distro
- Red Hat Enterprise Linux 7Operating Systems / linux-distro
- Red Hat Enterprise Linux 8.2 Advanced Update SupportOperating Systems / linux-distro
- Red Hat Enterprise Linux 8.2 Telecommunications Update ServiceOperating Systems / linux-distro
- Red Hat Enterprise Linux 8.2 Update Services for SAP SolutionsOperating Systems / linux-distro
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportOperating Systems / linux-distro
- Red Hat Enterprise Linux 8.4 Telecommunications Update ServiceOperating Systems / linux-distro
- Red Hat Enterprise Linux 8.4 Update Services for SAP SolutionsOperating Systems / linux-distro
And 8 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Scored 7.4 by NVD.
How it is reached
- Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
- Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
References in the record
- access.redhat.com/errata/RHSA-2024:1834
- access.redhat.com/errata/RHSA-2024:1835
- access.redhat.com/errata/RHSA-2024:1873
And 14 more references. See all after sign-in
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