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BoKS Server Agent CVE-2026-9864

| EUVDEUVD-2026-90889 MEDIUM
Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) (CWE-338)
2026-10-01 df4dee71-de3a-4139-9588-11b62fe6c0ff GHSA-rh95-jwc3-f9fr
4.8
CVSS 3.1 · Vendor: df4dee71-de3a-4139-9588-11b62fe6c0ff
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Estimate machine-account password generation time window
  2. Delivery
    Model adjoin weak-entropy keyspace
  3. Exploit
    Brute-force reduced candidate passwords
  4. Execution
    Recover AD machine-account credential
  5. Impact
    Authenticate as compromised machine account

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A04:2025 - Cryptographic Failures
ASVS 5.0
V11 - Cryptography Cryptographic PRNG selection
Exploitation Conditions

Exploitation requires a BoKS Server Agent that performed an Active Directory join or machine-account password renewal via the affected adjoin utility, producing a machine-account password with significantly reduced entropy. The attacker must be able to estimate the time at which that password was generated in order to narrow and predict the value - this timing dependency, reflected as AC:H, is the primary limiting factor. The flaw is scoped to AD-integrated BoKS deployments using adjoin; environments not joined to Active Directory or using externally managed machine-account credentials are not exposed, and impact is limited to predicting that specific machine-account credential rather than direct host compromise.

Impact

This is a moderate-severity cryptographic weakness (CVSS 4.8, CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N) rather than a high-urgency flaw. The vector lists AV:N and PR:N (no authentication required), but AC:H is the dominant limiter: successful exploitation requires the attacker to estimate the time window in which the machine-account password was generated and then brute-force a reduced-entropy keyspace, which is non-trivial and target-specific. The impact is scoped to low confidentiality and low integrity with no availability impact, consistent with recovering/predicting a single machine-account credential rather than full system takeover. No EPSS score, CISA KEV listing, or public POC is present in the provided data, so there is no evidence of active or widespread exploitation - this reads as a targeted, opportunistic weakness against specific deployments, not a mass-exploitation priority. One note: PR:N in the CVSS vector means it is technically unauthenticated, but exploitation realistically depends on the attacker having visibility into or the ability to estimate password-generation timing, so real-world attacker prerequisites are higher than the raw 'network/unauthenticated' framing implies.

Exploit ScenarioDerived

An attacker who can observe or infer when a BoKS Server Agent performed an Active Directory join or machine-account password renewal uses the known weak entropy of the adjoin utility's password generator to constrain and brute-force the resulting machine-account password. Having predicted the credential, they authenticate to Active Directory as that machine account. No public exploit code was identified at time of analysis, and the high attack complexity (AC:H) reflects the timing-estimation and search effort required.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
No patch listed yet 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 01, 2026

Predictable machine-account passwords produced by the adjoin utility in Fortra BoKS Server Agent can be guessed by a remote, unauthenticated attacker who can estimate when the password was generated, because the utility's generation routine yields significantly less entropy than intended. Rated CVSS 4.8 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N), the exposure is limited to AD-integrated deployments that ran an Active Directory join or machine-account password renewal through adjoin; the timing dependency required to narrow the password space is the principal barrier, reflected in the high attack-complexity metric. There is no confirmed active exploitation (not in CISA KEV) and no public exploit identified at time of analysis, and the impact is confined to predicting that specific machine-account credential rather than achieving direct host compromise.

RemediationAI

Apply the vendor fix as soon as Fortra publishes it: consult the product security advisory at https://www.fortra.com/security/advisories/product-security/fi-2026-018 to identify the patched BoKS Server Agent build and upgrade to that exact version - no specific fix version was included in the available intelligence, so the version number must be taken from the advisory rather than assumed. Because the vulnerable artifact is a stored credential, patching alone does not undo the exposure of passwords already generated, so immediately rotate every AD machine-account password that was created or renewed by adjoin, generating the replacement from a high-entropy external source instead of letting adjoin regenerate it (the trade-off is that any rotation performed before the code fix can itself reintroduce a weak secret, so rotate again after upgrading). Until patching is possible, the practical compensating controls are to stop using adjoin for join/renewal and provision machine credentials out of band, which breaks the automated AD integration workflow and requires manual lifecycle management; to shorten machine-account password lifetimes so a predicted value has a smaller useful window, which increases operational overhead and AD replication churn; and to restrict network reachability of the AD join/renewal channels to the specific management hosts that require them, which reduces the attacker population but does not remove the weakness for an attacker already positioned on the management network. Finally, add detection for anomalous or repeated authentication attempts against BoKS/AD machine accounts, since the high attack complexity here means a real attack would likely appear as iterative guessing rather than a single event.

Affected VersionsENISA

Core Privileged Access Manager (BoKS) 9.0.0.0 ≤9.0.0.5
Core Privileged Access Manager (BoKS) 8.1.0.0 ≤8.1.0.29

Affected Packages

euvd core_privileged_access_manager_boks no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The flaw is a CWE-338 weakness - use of a cryptographically weak pseudo-random number generator - in the adjoin utility of Fortra BoKS Server Agent, which automates joining a BoKS host to an Active Directory domain and periodically renewing the associated machine-account password. Machine-account secrets should be high-entropy random values, but here the password-generation path produces far fewer effective bits than intended, so an adversary who can approximate the generation timestamp can prune the candidate space and predict the credential. Because the CVSS vector is AV:N/AC:H/PR:N/UI:N with C:L/I:L/A:N, exploitation is remote and requires no prior authentication or user interaction, but is constrained by the need to estimate timing, and the consequence is limited to disclosure and possible misuse of that one AD machine credential - the advisory does not describe a path from the predicted password to code execution or loss of availability. Environments that are not AD-integrated, or that manage machine-account credentials outside adjoin, sit outside the vulnerable code path entirely.

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Severity by source

Vendor (df4dee71-de3a-4139-9588-11b62fe6c0ff) PRIMARY 4.8 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
vuln.today AI 4.8 MEDIUM

AC:H because exploitation needs password-generation timing estimation plus brute-forcing a reduced keyspace; PR:N as no prior auth is required; C:L/I:L for credential prediction, A:N as no availability impact.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (df4dee71-de3a-4139-9588-11b62fe6c0ff).

CVSS VectorVendor: df4dee71-de3a-4139-9588-11b62fe6c0ff

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

DescriptionCVE.org

Fortra BoKS Server Agent contains a predictable password generation vulnerability in the adjoin utility. Machine-account passwords generated during Active Directory join or password renewal operations may have significantly less entropy than intended, making them more susceptible to prediction by an attacker who can estimate when the password was generated.

Threat Intelligence Overview

EPSS Score
0.1%
Top 97% exploitable
Prevalence
Low
niche enterprise Unix/Linux privileged-access product, limited deployment footprint
Data Quality
4 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.1%
Patch available No
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
No
Human Impact· derived
Medium
Technical Impact
Partial

Priority Score

24
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +24
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

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