What is CVE-2023-2533?

CVE-2023-2533 is PaperCut MF/NG 22.0.10 (Build 65996 2023-03-27) - Remote code execution via CSRF. The supplied enrichment data classifies it as CSRF mapped to CWE-352 Cross-Site Request Forgery.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Yes: CISA KEV signal present. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

Is there a public exploit?

15 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2023-2533 using CVSS 8.8, EPSS 29%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

Publicly linked actor or ransomware signals in the supplied enrichment data: APT3 (), APT 28 (), APT35 (), MuddyWater (), Shadow Network (). Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Treat as emergency remediation because CISA KEV status is present. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

CISA KEVhighCSRFpublic exploit

CVE-2023-2533

CVE-2023-2533 — PaperCut MF/NG 22.0.10 (Build 65996 2023-03-27) - Remote code execution via CSRF

Q: Is it in CISA KEV?

Yes. The supplied enrichment data lists CVE-2023-2533 in CISA KEV with required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

A Cross-Site Request Forgery (CSRF) vulnerability has been identified in PaperCut NG/MF, which, under specific conditions, could potentially enable an attacker to alter security settings or execute arbitrary code. This could be exploited if the target is an admin with a current login session. Exploiting this would typically involve the possibility of deceiving an admin into clicking a specially crafted malicious link, potentially leading to unauthorized changes.

Published Jun 20, 2023Updated Jun 17, 2026Sources: NVD, PaperCut (CNA), CISA, FIRST EPSS, GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Confirmed

CISA KEV, listed Jul 28, 2025

EPSS

29%

ahead of 98% of scored CVEs

Affects

PaperCut

3 products listed

CVSS base

8.8

high · 2 sources

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade PaperCut NG/MF to a fixed release (21.2.12). Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Federal deadline Aug 18, 2025 — passed 412 days ago

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Treat as emergency remediation because CISA KEV status is present.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
PaperCut	PaperCut NG/MF	22.0.10 to < 2.1.1	Vulnerable
PaperCut	PaperCut NG/MF	21.2.12	Patched
PaperCut	PaperCut NG/MF	20.1.8	Patched

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

Required

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
8.4	CVSS 3.1	high	1.7	6	fluidattacks.com (CNA), PaperCut (CNA)
8.8	CVSS 3.1	high	2.8	5.9	NVD

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-352 · Cross-Site Request Forgery (CSRF)

Gain Privileges or Assume Identity
Bypass Protection Mechanism
Read Application Data
Modify Application Data

Mitigation: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, use anti-CSRF packages such as the OWASP CSRFGuard. [REF-330] Another example is the ESAPI Session Management control, which includes a component for CSRF. [REF-45]

Weakness & attack patterns

CWE-352Cross-Site Request Forgery

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-462 · Cross-Domain Search TimingCAPEC-467 · Cross Site IdentificationCAPEC-62 · Cross Site Request ForgeryCAPEC-111 · JSON Hijacking (aka JavaScript Hijacking)

CISA KEV details

CISA lists a CVE here once it has evidence of exploitation against real targets.

CISAThat month →

Listed

Jul 28, 2025

Federal deadline

Aug 18, 2025

passed 412 days ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Exploit entries

Exploit-DB and CTI exploit indexes

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /MF.
Prioritize edge telemetry for network-reachable PaperCut NG/MF.
Monitor for scanner or exploit-pattern traffic after 15 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Groups associated with this CVE

Groups reported in connection with this vulnerability. A reported association, not a confirmed observation of that group using it — and not scoped to any sector or campaign.

APT3APT 28APT35MuddyWaterShadow Network

2 more threat groups on this CVEShowing 5 of 7 · Attribution, campaigns and the malware each one runsUnlock free

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 8.8 (AV:N)
Jun 17, 2026 · NVD
2025
Bulletin released on NIST.
Jul 30, 2025 · SOCRadar CTI
Bulletin released on NIST.
Jul 30, 2025 · SOCRadar CTI
Bulletin released on NIST.
Jul 30, 2025 · SOCRadar CTI
Added to CISA KEV catalog
Jul 28, 2025 · CISA
2023
Initial · CVE published
Jun 20, 2023 · NVD

Source activity

Readings a source repeats on a schedule, counted rather than listed.

14×SVRS was changedJul 30, 2025 – Aug 24, 2025 · SOCRadar CTI
5×ModifiedJul 30, 2025 – Oct 24, 2025 · SOCRadar CTI
5×TweetsJul 30, 2025 – Aug 22, 2025 · SOCRadar CTI
1×Github_Repos · Github repository created, allinsthon/CVE-2023-2533Jul 30, 2025 · SOCRadar CTI
1×1 time mentioned on 1 Telegram channelJul 30, 2025 · SOCRadar CTI

References

5 on the record

fluidattacks.com/advisories/arcangel/
Exploit, Third Party Advisory, NIST
www.papercut.com/kb/Main/SecurityBulletinJune2023
Vendor Advisory, NIST
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-2533
US Government Resource, NIST
www.papercut.com/
NIST
nvd.nist.gov/vuln/detail/CVE-2023-2533
Vendor Advisory

Coverage

2 stories from the feeds we poll

Elsewhere on this site

PaperCutevery CVE for this vendor
July 2025what else CISA listed
CSRFsame class
CWE-352other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2023-2533 is PaperCut MF/NG 22.0.10 (Build 65996 2023-03-27) - Remote code execution via CSRF, a high vulnerability affecting PaperCut NG/MF from PaperCut. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 15 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 8.8 describes technical severity, while EPSS 29% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.