ZyXEL ZyWALL/USG series devices have a Bleichenbacher vulnerability in their Internet Key Exchange (IKE) handshake implementation used for I
ZyXEL ZyWALL/USG series devices have a Bleichenbacher vulnerability in their Internet Key Exchange (IKE) handshake implementation used for IPsec based VPN connections.
- Published
- Aug 15, 2018
- Updated
- Jun 16, 2026
- EPSS
- 1.0% · 60th percentile
- CWE
- —
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Report tools
Action score
23
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.0%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| zyxel | zywall 110 firmware | cpe:2.3:o:zyxel:zywall_110_firmware |
| zyxel | zywall 110 | cpe:2.3:h:zyxel:zywall_110 |
| zyxel | zywall 1100 firmware | cpe:2.3:o:zyxel:zywall_1100_firmware |
| zyxel | zywall 1100 | cpe:2.3:h:zyxel:zywall_1100 |
| zyxel | zywall 310 firmware | cpe:2.3:o:zyxel:zywall_310_firmware |
| zyxel | zywall 310 | cpe:2.3:h:zyxel:zywall_310 |
| zyxel | zywall vpn 50 firmware | cpe:2.3:o:zyxel:zywall_vpn_50_firmware |
| zyxel | zywall vpn 50 | cpe:2.3:h:zyxel:zywall_vpn_50 |
| zyxel | zywall vpn 100 firmware | cpe:2.3:o:zyxel:zywall_vpn_100_firmware |
| zyxel | zywall vpn 100 | cpe:2.3:h:zyxel:zywall_vpn_100 |
| zyxel | zywall vpn 300 firmware | cpe:2.3:o:zyxel:zywall_vpn_300_firmware |
| zyxel | zywall vpn 300 | cpe:2.3:h:zyxel:zywall_vpn_300 |
and 22 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- zyxel usg 110 firmwareall versions
- zyxel usg 1100 firmwareall versions
- zyxel usg 1900 firmwareall versions
- zyxel usg 20w firmwareall versions
- zyxel usg 20w-vpn firmwareall versions
- zyxel usg 2200-vpn firmwareall versions
- zyxel usg 310 firmwareall versions
- zyxel usg 40 firmwareall versions
- zyxel usg 40w firmwareall versions
- zyxel usg 60 firmwareall versions
- zyxel usg 60w firmwareall versions
- zyxel zywall 110 firmwareall versions
- zyxel zywall 1100 firmwareall versions
- zyxel zywall 310 firmwareall versions
- zyxel zywall vpn 100 firmwareall versions
- zyxel zywall vpn 300 firmwareall versions
- zyxel zywall vpn 50 firmwareall versions
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
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
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.
No credits in the CNA record.
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.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
—
CVSS vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
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
- ftp://ftp.zyxel.com/USG110/firmware/USG110_4.32%28AAPH.0%29C0_2.pdf
- web-in-security.blogspot.com/2018/08/practical-bleichenbacher-attacks-on-ipsec-ike.html
- www.zyxel.com/support/bleichenbacher_attack_vulnerability.shtml
Vendor advisories and official records. Exploit/PoC links are deliberately left out.