Cyber Resilience

CVE-2025-8549

Pybbs Project Pybbs ≤ 6.0.0

Public PoC
Published
05 August 2025
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v4 2.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/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
EPSS Score 0.0043 36th percentile
Risk Priority 25 floored blend · peak EPSS

Summary

CVE-2025-8549 is a low-severity Weak Password Requirements (CWE-521) vulnerability in Pybbs Project Pybbs. Its CVSS base score is 2.9 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Brute Force (T1110); ranked at the 36th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to IA-5 (Authenticator Management) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

A vulnerability was found in atjiu pybbs up to 6.0.0. It has been classified as critical. Affected is the function update of the file src/main/java/co/yiiu/pybbs/controller/admin/UserAdminController.java. The manipulation leads to weak password requirements. It is possible to launch the attack remotely.…

more

The complexity of an attack is rather high. The exploitability is told to be difficult. The exploit has been disclosed to the public and may be used. The patch is identified as d09cb19a8e7d7e5151282926ada54080244d499f. It is recommended to apply a patch to fix this issue.

CWE(s)
CWE-521

Related Threats

MITRE ATT&CK Enterprise Techniques

T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
attack.mitre.org →
T1110.002 Password Cracking Credential Access
Adversaries may use password cracking to attempt to recover usable credentials, such as plaintext passwords, when credential material such as password hashes are obtained.
attack.mitre.org →
T1110.003 Password Spraying Credential Access
Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials.
attack.mitre.org →
T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
attack.mitre.org →
T1558.003 Kerberoasting Credential Access
Adversaries may abuse a valid Kerberos ticket-granting ticket (TGT) or sniff network traffic to obtain a ticket-granting service (TGS) ticket that may be vulnerable to [Brute Force](https://attack.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-8546Same product: Pybbs Project Pybbs
CVE-2025-12297Same product: Pybbs Project Pybbs
CVE-2025-8547Same product: Pybbs Project Pybbs
CVE-2025-8550Same product: Pybbs Project Pybbs
CVE-2025-8553Same product: Pybbs Project Pybbs
CVE-2025-8554Same product: Pybbs Project Pybbs
CVE-2025-8555Same product: Pybbs Project Pybbs
CVE-2025-8548Same product: Pybbs Project Pybbs
CVE-2025-8551Same product: Pybbs Project Pybbs
CVE-2025-8814Same product: Pybbs Project Pybbs

Affected Assets

pybbs project
pybbs
≤ 6.0.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)
  • V6.2.4
  • V6.2.9
  • V6.2.12
  • V6.4.1

Mitigating Controls (NIST 800-53 r5) AI

IA-5 Authenticator Management good match

IA-5 directly requires organizations to enforce strength, complexity, and change rules for passwords and other authenticators at issuance and reset.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 full match
prevents

Explicitly requires enforcing minimum password strength as part of authentication.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.17 Authentication information mostly match
prevents

Enforcing minimum length, complexity, non-dictionary, and non-reuse rules directly counters weak password policies that allow attackers to guess or brute-force credentials.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 7 (2 rules)
  • V-204424 The Red Hat Enterprise Linux operating system must not allow accounts configured with blank or null passwords. prevents CWE-521
  • V-204425 The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow authentication using an empty password. prevents CWE-521

References