CVE-2023-45236VulnerabilityPublished 16 Jan 2024Updated 4 Nov 2025

CVE-2023-45236: TianoCore edk2 · Information Exposure

Affects TianoCore edk2Source CVE Database V5

Not known to be exploited · CVSS 5.8 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.8Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.9% chance of exploitation in 30 days – higher than 62% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Jan 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

1. Monitor TianoCore and edk2 project repositories and security advisories for official patches addressing CVE-2023-45236 and apply them promptly once available. 2. Implement network-level protections such as TCP ISN randomization on network devices and endpoints to reduce predictability of sequence numbers. 3. Employ network segmentation and strict firewall rules to limit exposure of vulnerable firmware network interfaces to untrusted networks. 4. Use secure communication protocols with strong encryption (e.g., TLS) to protect data in transit beyond the firmware layer. 5. Conduct firmware inventory and validation to identify devices running the affected edk2-stable202308 version and prioritize their update or replacement. 6. Deploy network intrusion detection systems (NIDS) capable of detecting anomalous TCP sequence behavior indicative of exploitation attempts. 7. Educate IT and security teams about the nature of TCP ISN prediction attacks to enhance incident response readiness. 8. Collaborate with hardware vendors to confirm firmware versions and coordinate patch deployment schedules.

Description

EDK2's Network Package is susceptible to a predictable TCP Initial Sequence Number. This vulnerability can be exploited by an attacker to gain unauthorized access and potentially lead to a loss of Confidentiality.

Impact

For European organizations, this vulnerability poses a risk primarily to confidentiality of network communications during early firmware network initialization phases. Organizations relying on hardware or firmware that incorporates the affected edk2-stable202308 version may be vulnerable to network-based attacks that could expose sensitive data. This is particularly concerning for sectors such as telecommunications, critical infrastructure, finance, and government, where firmware-level vulnerabilities can undermine trust and security. The vulnerability could facilitate man-in-the-middle attacks or session hijacking, potentially leading to data leaks or unauthorized access to internal systems. Although the vulnerability does not affect system integrity or availability directly, the exposure of sensitive information can have cascading effects, including compliance violations under GDPR and other data protection regulations. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits targeting this flaw.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 4 Nov 2025, 18:53 UTC

WeaknessesCWE-200

Technical details

References

Community reviews

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