A vulnerability was discovered in Linux, FreeBSD, OpenBSD, MacOS, iOS, and Android that allows a malicious access point, or an adjacent user
A vulnerability was discovered in Linux, FreeBSD, OpenBSD, MacOS, iOS, and Android that allows a malicious access point, or an adjacent user, to determine if a connected user is using a VPN, make positive inferences about the websites they are visiting, and determine the correct sequence and acknowledgement numbers in use, allowing the bad actor to inject data into the TCP stream. This provides everything that is needed for an attacker to hijack active connections inside the VPN tunnel.
- Published
- Dec 11, 2019
- Updated
- Jun 16, 2026
- EPSS
- 0.8% · 56th percentile
- CWE
- CWE-300
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Report tools
Action score
29
Monitor
Low priority for now.
- CVSS
- 29 / 40 · 7.4 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.8%
CNA vs NVD score
- NVD
- 7.4
- CNA · redhat
- 7.4
- agree
CVSS:3.0/AV:A/AC:L/PR:L/UI:R/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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; 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 helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| freebsd | freebsd | cpe:2.3:o:freebsd:freebsd |
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
| openbsd | openbsd | cpe:2.3:o:openbsd:openbsd |
| apple | ipados | cpe:2.3:o:apple:ipados |
| apple | iphone os | cpe:2.3:o:apple:iphone_os |
| apple | mac os x | cpe:2.3:o:apple:mac_os_x |
| apple | macos | cpe:2.3:o:apple:macos |
| apple | tvos | cpe:2.3:o:apple:tvos |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- apple ipadosbefore 13.6
- apple iphone osbefore 13.6
- apple mac os xbefore 10.15.6
- apple macos11.0
- apple tvosbefore 13.4.8
- freebsd freebsdall versions
- linux linux kernelall versions
- openbsd openbsdall versions
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
Red Hat VPN
- n/aaffected
Same product
freebsd: all recordsOther highest-scoring records for the same primary product.
- CVE-2006-0900nfsd in FreeBSD 6.0 kernel allows remote attackers to cause a denial of service via a crafted NFS mount request, as demonstrated by the Prot51Plan
- CVE-2018-17157In FreeBSD before 11.2-STABLE(r340854) and 11.2-RELEASE-p5, an integer overflow error when handling opcodes can cause memory corruption by s46Plan
- CVE-2010-1938Off-by-one error in the __opiereadrec function in readrec.c in libopie in OPIE 2.4.1-test1 and earlier, as used on FreeBSD 6.4 through 8.1-P44Plan
- CVE-2006-4304Buffer overflow in the sppp driver in FreeBSD 4.11 through 6.1, NetBSD 2.0 through 4.0 beta before 20060823, and OpenBSD 3.8 and 3.9 before 44Plan
- CVE-2020-7457In FreeBSD 12.1-STABLE before r359565, 12.1-RELEASE before p7, 11.4-STABLE before r362975, 11.4-RELEASE before p1, and 11.3-RELEASE before p42Plan
- CVE-2008-2427Stack-based buffer overflow in NConvert 4.92, GFL SDK 2.82, and XnView 1.93.6 on Windows and 1.70 on Linux and FreeBSD allows user-assisted 42Plan
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-20-325 · May 8, 2020(IBM Ürünleri Güvenlik Güncellemesi)
Technical details
Attack conditions
- Someone on the same network segment can trigger it.
- A low-privileged account is enough.
- A user must open a link or visit a page.
- 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
- Adjacent
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-300 · Channel Accessible by Non-EndpointCVSS vector
CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
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.
Attack patterns (CAPEC)
- Leveraging Active Adversary in the Middle Attacks to Bypass Same Origin PolicyCAPEC-466Medium
- Utilizing REST's Trust in the System Resource to Obtain Sensitive DataCAPEC-57likelihood: Medium · Very High
- DNS BlockingCAPEC-589
- IP Address BlockingCAPEC-590likelihood: Low · High
- WiFi MAC Address TrackingCAPEC-612Low
- WiFi SSID TrackingCAPEC-613Low
- Evil Twin Wi-Fi AttackCAPEC-615Low
- Adversary in the Browser (AiTB)CAPEC-662likelihood: High · Very High
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- seclists.org/fulldisclosure/2020/Dec/32
- seclists.org/fulldisclosure/2020/Jul/23
- seclists.org/fulldisclosure/2020/Jul/24
- seclists.org/fulldisclosure/2020/Jul/25
- seclists.org/fulldisclosure/2020/Nov/20
- www.openwall.com/lists/oss-security/2020/08/13/2
- www.openwall.com/lists/oss-security/2020/10/07/3
- www.openwall.com/lists/oss-security/2021/07/05/1
- bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14899
- openvpn.net/security-advisory/no-flaws-found-in-openvpn-software/
- support.apple.com/kb/HT211288
- support.apple.com/kb/HT211289
- support.apple.com/kb/HT211290
- support.apple.com/kb/HT211850
- support.apple.com/kb/HT211931
Vendor advisories and official records. Exploit/PoC links are deliberately left out.