CVE-2023-35838 json
The WireGuard client 0.5.3 on Windows insecurely configures the operating system and firewall such that traffic to a local network that use…
published 2023-08-09 3 y ago modified 2026-06-17 4 mo ago also PYSEC-2023-321 , EUVD-2023-39833
- cvss
- 5.7
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 53%
- public exploits
- 0
- none known
Summary
The WireGuard client 0.5.3 on Windows insecurely configures the operating system and firewall such that traffic to a local network that uses non-RFC1918 IP addresses is blocked. This allows an adversary to trick the victim into blocking IP traffic to selected IP addresses and services even while the VPN is enabled. NOTE: the tunnelcrack.mathyvanhoef.com website uses this CVE ID to refer more generally to "LocalNet attack resulting in the blocking of traffic" rather than to only WireGuard.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 y ago
Exploit prediction
0.69% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- tunnelcrack.mathyvanhoef.com https://tunnelcrack.mathyvanhoef.com/details.html referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.7 | CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
| OSV | 3.1 | 5.7 | CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | wireguard | <=0.5.3 |
no fix listed |
Classification
- Weakness
-
- CWE-610 Externally Controlled Reference to a Resource in Another Sphere
References
-
tunnelcrack.mathyvanhoef.com
/details.html
exploit, third-party-advisory, evidence
-
wireguard.com
product, web
-
psirt.global.sonicwall.com
/vuln-detail/SNWLID-2023-0015
web
Sources
- CVE List CVE-2023-35838
- NVD CVE-2023-35838
- OSV PYSEC-2023-321
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.