CVE-2023-28503 | Authentication bypass in UniRPC's udadmin service

Rocket Software UniData versions prior to 8.2.4 build 3003 and UniVerse versions prior to 11.3.5 build 1001 or 12.2.1 build 2002 suffer from an authentication bypass vulnerability, where a special username with a deterministic password can be leveraged to bypass authentication checks and execute OS commands as the root user.

Published: 2023-03-29 Last update: 2025-02-18 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-28503 is rated High Risk (78.8/100): CVSS Critical severity, with high exploitation likelihood (EPSS 72.32%, 99th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +7.55% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-28503

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-25 64.77% 72.32% +7.55%
2 2026-04-25 66.79% 64.77% -2.02%
3 2026-04-16 66.79%

Full EPSS history (29 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-28503

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2023-28503

Affected software / configurations for CVE-2023-28503

Vendor Product Version Raw CPE
rocketsoftware unidata <= 8.2.4 cpe:2.3:a:rocketsoftware:unidata:*:*:*:*:*:*:*:*
rocketsoftware universe <= 11.3.5 cpe:2.3:a:rocketsoftware:universe:*:*:*:*:*:*:*:*
rocketsoftware universe >= 12.0.0, <= 12.2.1 cpe:2.3:a:rocketsoftware:universe:*:*:*:*:*:*:*:*

References for CVE-2023-28503

cvelogic Threat Intelligence