CVE-2023-45236: Predictable TCP ISNs in EDK II Network Package
Vulnerability summary
CVE-2023-45236 is a high (CVSS 7.5) vulnerability in tianocore edk2. EPSS estimates a 0.99% chance of exploitation in the next 30 days, higher than 62.6% of scored vulnerabilities.
Not severe (CVSS 5.8, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 11 · Related 9Timeline
- 16-01-2024PublishedVulnerability first disclosed.
- 04-11-2025Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 4 sources · 1 version- CVE.orgCNA5.8MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:NDiffers
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.99%
Chance of exploitation in the next 30 days
Percentile
63%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.99% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-200Exposure of Sensitive Information to an Unauthorized ActorThe product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
- CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- edk2All versions (No fix recorded) | < 2024.05-1
Tianocore1 product
- edk2edk2-stable202308 | ≤ 202311
Ubuntu1 product
- edk2All versions (No fix recorded)
3 vendors · 3 products
References
12 links- www.openwall.com/lists/oss-security/2024/01/16/2Mailing List
