WebPerfect Image Suite: External Control of File Name or Path
CVE-2026-39907 is a critical-severity external control of file name or path vulnerability in WebPerfect Image Suite from Unisys, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected WebPerfect Image Suite versions: 3.0.3960.22810; 3.0.3960.22604. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.64% chance of exploitation within 30 days, higher than 51% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of WebPerfect Image Suite you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Unisys | WebPerfect Image Suite | 3.0.3960.22810; 3.0.3960.22604 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.0 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 10.0 | Critical | NVD |
Official description
Unisys WebPerfect Image Suite versions 3.0.3960.22810 and 3.0.3960.22604 expose an unauthenticated WCF SOAP endpoint on TCP port 1208 that accepts unsanitized file paths in the ReadLicense action's LFName parameter, allowing remote attackers to trigger SMB connections and leak NTLMv2 machine-account hashes. Attackers can submit crafted SOAP requests with UNC paths to force the server to initiate outbound SMB connections, exposing authentication credentials that may be relayed for privilege escalation or lateral movement within the network.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: External Control of File Name or Path
The product allows user input to control or influence paths or file names that are used in filesystem operations.
How developers prevent this class of flaw
- When the set of filenames is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames, and reject all other inputs. For example, ID 1 could map to inbox.txt and ID 2 could map to profile.txt. Features such as the ESAPI AccessReferenceMap provide this capability.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict all access to files within a particular directory. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More External Control of File Name or Path vulnerabilities (CWE-73)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
Technical write-ups (may include proof of concept)
- gist.github.com/VAMorales/be3e4ed472c51794493c1256cce16129Exploit, Third Party Advisory
Other references
Other vulnerabilities in WebPerfect Image Suite
- 10.0 Critical severity
Recent External Control of File Name or Path vulnerabilities
- 8.1 High severity
- 7.1 High severity
- 7.8 High severity
- 7.1 High severity
- 9.8 Critical severity
- 8.4 High severity
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