This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914).
This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914). Authentication is not required to exploit this vulnerability. The specific flaw exists within the SetupCompleted class. The issue results from improper access control. An attacker can leverage this vulnerability to bypass authentication and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-18987.
- Published
- Apr 20, 2023
- Updated
- Jun 17, 2026
- EPSS
- 100.0% · 100th percentile
- CWE
- CWE-284
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Report tools
Action score
99
Now
Patch today or shut off access.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 30 / 30 · Listed
- EPSS
- 30 / 30 · 100.0%
CISA SSVC decision
- Exploitation
- active
- Automatable
- yes
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 9.8
- CNA · zdi
- 9.8
- agree
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Actively exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on Apr 21, 2023. That signals real attacks, not theory.
Remediation deadline for government agencies: May 12, 2023.
Known to be used in ransomware campaigns.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| papercut | papercut mf | cpe:2.3:a:papercut:papercut_mf |
| papercut | papercut ng | cpe:2.3:a:papercut:papercut_ng |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- papercut papercut mf8.0 and later · before 20.1.7
- papercut papercut mf21.0.0 and later · before 21.2.11
- papercut papercut mf22.0.0 and later · before 22.0.9
- papercut papercut ng8.0 and later · before 20.1.7
- papercut papercut ng21.0.0 and later · before 21.2.11
- papercut papercut ng22.0.0 and later · before 22.0.9
Versions reported by the vendor
Affected version ranges reported by the assigning authority (zdi). Independent of NVD's CPE analysis and usually ahead of it.
PaperCut NG
- 22.0.5 (Build 63914)affected
Same product
papercut: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-27351This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914).KEV83Now
- CVE-2023-2533PaperCut MF/NG 22.0.10 (Build 65996 2023-03-27) - Remote code execution via CSRFKEV74This week
- CVE-2026-82078PaperCut MF/NG: Unsafe Dynamic Class Loading in Database ConnectorKEV68This week
- CVE-2026-81578PaperCut MF/NG: Authentication BypassKEV66This week
- CVE-2023-39143PaperCut NG and PaperCut MF before 22.1.3 on Windows allow path traversal, enabling attackers to upload, read, or delete arbitrary files.63This week
- CVE-2024-1222Incorrect authorization controls in PaperCut NG/MF APIs58Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
- Exploit-DB entry ×2
- Nuclei detection template ×1
- Proof-of-concept repository on GitHub ×14
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | webapps | 2023-04-25 |
| Exploit-DB entry | webapps | 2023-05-23 |
| Metasploit module | exploit/multi/http/papercut_ng_auth_bypassPaperCut PaperCutNG Authentication Bypassexploit | 2023-03-13 |
| Nuclei detection template | Nuclei template CVE-2023-27350 | — |
| Proof-of-concept repository on GitHub | stars:5 | 2023-04-21 |
| Proof-of-concept repository on GitHub | stars:12 | 2023-04-21 |
| Proof-of-concept repository on GitHub | stars:56 | 2023-04-22 |
| Proof-of-concept repository on GitHub | stars:9 | 2023-04-25 |
| Proof-of-concept repository on GitHub | stars:2 | 2023-05-27 |
| Proof-of-concept repository on GitHub | stars:0 | 2023-06-13 |
| Proof-of-concept repository on GitHub | stars:0 | 2024-04-19 |
| Proof-of-concept repository on GitHub | stars:0 | 2024-05-10 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Metasploit-39 d
- Published
- First PoCsame day
- CISA KEVsame day
- TodaySep 29, 2026+1258 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-284 · Improper Access ControlCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Embedding Scripts within ScriptsCAPEC-19likelihood: High · High
- Malicious Logic InsertionCAPEC-441likelihood: Medium · High
- Modification of Windows Service ConfigurationCAPEC-478likelihood: Low · High
- Malicious Root CertificateCAPEC-479likelihood: Low · Low
- Intent SpoofCAPEC-502
- WebView ExposureCAPEC-503
- Data Injected During ConfigurationCAPEC-536likelihood: Low · High
- Incomplete Data Deletion in a Multi-Tenant EnvironmentCAPEC-546likelihood: Low · Medium
ATT&CK techniques
- RootkitT1014
- Obfuscated Files or Information: Embedded PayloadsT1027.009
- Boot or Logon Initialization ScriptsT1037
- Taint shared contentT1080
- Server Software Component: Terminal Services DLLT1505.005
- Pre-OS Boot:BootkitT1542.003
- Create or Modify System ProcessT1543
- Create or Modify System Process: Launch AgentT1543.001
- Create or Modify System Process:Windows ServiceT1543.003
- Create or Modify System Process: Launch DaemonT1543.004
- Event Triggered Execution:Change Default File AssociationT1546.001
- Event Triggered Execution:.bash_profile and .bashrcT1546.004
- Event Triggered Execution: Accessibility FeaturesT1546.008
- Event Triggered Execution: Installer PackagesT1546.016
- Boot or Logon Autostart ExecutionT1547
- Boot or Logon Autostart Execution:Kernel Modules and ExtensionsT1547.006
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- packetstormsecurity.com/files/171982/PaperCut-MF-NG-Authentication-Bypass-Remote-Code-Execution.html
- news.sophos.com/en-us/2023/04/27/increased-exploitation-of-papercut-drawing-blood-around-the-internet/
- www.papercut.com/kb/Main/PO-1216-and-PO-1219
- www.zerodayinitiative.com/advisories/ZDI-23-233/
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27350
Vendor advisories and official records. Exploit/PoC links are deliberately left out.