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NVD / CVE Program· CNA ConnectWise

CVE-2025-3935: ScreenConnect Exposure to ASP.NET ViewState Code Injection

HighCVSS 7.2 · v3.1KEVWeaponized No fix recorded

Noroxi assessment

Priority: Plan (action score 59/100)

  • CISA has confirmed exploitation in the wild (Jun 2, 2025). Remediation deadline for US federal agencies: Jun 23, 2025.
  • Probability of exploitation in the next 30 days: 3.5% (FIRST EPSS); higher than 89.6% of all records.
  • Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Add it to your regular patch cycle. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

ScreenConnect versions 25.2.3 and earlier versions may be susceptible to a ViewState code injection attack. ASP.NET Web Forms use ViewState to preserve page and control state, with data encoded using Base64 protected by machine keys.  It is important to note that to obtain these machine keys, privileged system level access must be obtained. If these machine keys are compromised, attackers could create and send a malicious ViewState to the website, potentially leading to remote code execution on the server.  The risk does not originate from a vulnerability introduced by ScreenConnect, but from platform level behavior.  This had no direct impact to ScreenConnect Client. ScreenConnect 2025.4 patch disables ViewState and removes any dependency on it.

Published
Apr 25, 2025
Updated
Jun 17, 2026
EPSS
3.5% · 89th percentile

Report tools

JSON

Action score

59

Plan

Add it to your regular patch cycle.

CVSS
28 / 40 · 7.2 / 10
CISA KEV
30 / 30 · Listed
EPSS
1 / 30 · 3.5%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.2
CNA · ConnectWise
8.1
0.9 point gap

CVSS:3.1/AV:N/AC:H/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 Jun 2, 2025. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jun 23, 2025.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-3935

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
connectwisescreenconnect

Versions reported by the vendor

Affected version ranges reported by the assigning authority (ConnectWise). Independent of NVD's CPE analysis and usually ahead of it.

  • ConnectWise ScreenConnect

    • <25.2.3affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • connectwise screenconnectbefore 25.2.4

Same product

connectwise: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-1709Authentication bypass using an alternate path or channelKEV
    100Now
  • CVE-2024-1708Improper limitation of a pathname to a restricted directory (“path traversal”)KEV
    92Now
  • CVE-2026-84869ScreenConnect Client: Guest-to-Host File Execution via File-Transfer ActionsKEV
    69This week

Published before and after this one in the same product

  • ← EarlierCVE-2022-36781Sep 28, 2022 · ConnectWise - ScreenConnect Session Code Bypass
    21Monitor
  • Later →CVE-2025-14265Dec 11, 2025 · Improper server-side validation in ScreenConnect extension framework
    36Monitor
  • Later →CVE-2025-14823Dec 18, 2025 · Certificate Signing Extension Returns Encrypted Values
    21Monitor

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.

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.

  1. Published
  2. CISA KEV+37 d
  3. TodayNov 14, 2026+567 d

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • Administrator privileges are 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
High
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

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

nvd-primary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python
payload = sock.recv(65536)job = pickle.loads(payload)

Fixed

python
payload = sock.recv(65536)if not hmac.compare_digest(sign(payload), header_sig):    raise PermissionError("invalid signature")job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records