CWE-342
AllowedPredictable Exact Value from Previous Values
Abstraction: Base · Status: Draft
An exact value or random number can be precisely predicted by observing previous values.
12 vulnerabilities reference this CWE, most recent first.
GHSA-JQ6Q-C5MF-GJCV
Vulnerability from github – Published: 2022-05-17 03:45 – Updated: 2025-09-05 21:32Eaton Cooper Power Systems ProView 4.0 and 5.0 before 5.0 11 on Form 6 controls and Idea and IdeaPLUS relays generates TCP initial sequence number (ISN) values linearly, which makes it easier for remote attackers to spoof TCP sessions by predicting an ISN value.
{
"affected": [],
"aliases": [
"CVE-2014-9196"
],
"database_specific": {
"cwe_ids": [
"CWE-342"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2015-07-20T01:59:00Z",
"severity": "HIGH"
},
"details": "Eaton Cooper Power Systems ProView 4.0 and 5.0 before 5.0 11 on Form 6 controls and Idea and IdeaPLUS relays generates TCP initial sequence number (ISN) values linearly, which makes it easier for remote attackers to spoof TCP sessions by predicting an ISN value.",
"id": "GHSA-jq6q-c5mf-gjcv",
"modified": "2025-09-05T21:32:35Z",
"published": "2022-05-17T03:45:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2014-9196"
},
{
"type": "WEB",
"url": "https://ics-cert.us-cert.gov/advisories/ICSA-15-006-01"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-15-006-01"
},
{
"type": "WEB",
"url": "https://www.eaton.com/cybersecurity"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/75936"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-MH3H-4J34-54MR
Vulnerability from github – Published: 2026-09-27 18:30 – Updated: 2026-09-27 18:30Predictable exact value from previous values vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.
This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23.
{
"affected": [],
"aliases": [
"CVE-2026-88778"
],
"database_specific": {
"cwe_ids": [
"CWE-342"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-27T17:16:57Z",
"severity": "HIGH"
},
"details": "Predictable exact value from previous values vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway.\n\nThis issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23.",
"id": "GHSA-mh3h-4j34-54mr",
"modified": "2026-09-27T18:30:23Z",
"published": "2026-09-27T18:30:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-88778"
},
{
"type": "WEB",
"url": "https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX697096"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
Mitigation
Increase the entropy used to seed a PRNG.
Mitigation MIT-2
Strategy: Libraries or Frameworks
Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").
Mitigation MIT-50
Use a PRNG that periodically re-seeds itself using input from high-quality sources, such as hardware devices with high entropy. However, do not re-seed too frequently, or else the entropy source might block.
No CAPEC attack patterns related to this CWE.