process_http_response in OpenConnect before 8.05 has a Buffer Overflow when a malicious server uses HTTP chunked encoding with crafted chunk
Noroxi assessment
Priority: Plan (action score 40/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 3.4% (FIRST EPSS); higher than 88.8% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: openconnect (Debian:10) 8.02-1+deb10u1; openconnect (Debian:12) 8.02-1.1; openconnect (Debian:8) 6.00-2+deb8u1.
Add it to your regular patch cycle. Upgrade to openconnect (Debian:10) 8.02-1+deb10u1; openconnect (Debian:12) 8.02-1.1; openconnect (Debian:8) 6.00-2+deb8u1 or later.
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 · FIRST EPSS
process_http_response in OpenConnect before 8.05 has a Buffer Overflow when a malicious server uses HTTP chunked encoding with crafted chunk sizes.
- Published
- Sep 17, 2019
- Updated
- Jun 16, 2026
- EPSS
- 3.4% · 88th percentile
- CWE
- CWE-120
Report tools
Action score
40
Plan
Add it to your regular patch cycle.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 3.4%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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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.
We use this product, ask for helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| infradead | openconnect | cpe:2.3:a:infradead:openconnect |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| canonical | ubuntu linux | cpe:2.3:o:canonical:ubuntu_linux |
| opensuse | leap | cpe:2.3:o:opensuse:leap |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- canonical ubuntu linux18.04
- debian debian linux10.0
- debian debian linux8.0
- debian debian linux9.0
- fedoraproject fedora29
- fedoraproject fedora30
- fedoraproject fedora31
- infradead openconnectbefore 8.05
- opensuse leap15.0
- opensuse leap15.1
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:10 | openconnect | before 8.02-1+deb10u1 | 8.02-1+deb10u1 |
| Debian:12 | openconnect | before 8.02-1.1 | 8.02-1.1 |
| Debian:8 | openconnect | before 6.00-2+deb8u1 | 6.00-2+deb8u1 |
| Debian:9 | openconnect | before 7.08-1+deb9u1 | 7.08-1+deb9u1 |
| openSUSE:Leap 15.0 | openconnect | before 7.08-lp150.5.3.1 | 7.08-lp150.5.3.1 |
| openSUSE:Leap 15.1 | openconnect | before 7.08-lp151.6.3.1 | 7.08-lp151.6.3.1 |
| SUSE:Linux Enterprise Desktop 12 SP4 | openconnect | before 7.08-3.4.1 | 7.08-3.4.1 |
| SUSE:Linux Enterprise Workstation Extension 15 | openconnect | before 7.08-6.3.1 | 7.08-6.3.1 |
Same product
infradead: all recordsOther highest-scoring records for the same primary product.
- CVE-2020-12823OpenConnect 8.09 has a buffer overflow, causing a denial of service (application crash) or possibly unspecified other impact, via crafted ce40Plan
- CVE-2013-7098OpenConnect VPN client with GnuTLS before 5.02 contains a heap overflow if MTU is increased on reconnection.39Monitor
- CVE-2012-3291Heap-based buffer overflow in OpenConnect 3.18 allows remote servers to cause a denial of service via a crafted greeting banner.32Monitor
- CVE-2010-3901OpenConnect before 2.25 does not properly validate X.509 certificates, which allows man-in-the-middle attackers to spoof arbitrary AnyConnec25Monitor
- CVE-2020-12105OpenConnect through 8.08 mishandles negative return values from X509_check_ function calls, which might assist attackers in performing man-i24Monitor
- CVE-2012-6128Multiple stack-based buffer overflows in http.c in OpenConnect before 4.08 allow remote VPN gateways to cause a denial of service (applicati21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:openconnect | 8.02-1.1 · Debian:12 | Package registry (OSV) |
| opensuse:openconnect | 7.08-lp151.6.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| suse:openconnect | 7.08-6.3.1 · SUSE:Linux Enterprise Workstation Extension 15 | Package registry (OSV) |
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.
- 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Root cause
When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.
The bug in code
The whole CWE-120 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
char buf[256];memcpy(buf, pkt->data, pkt->len);Fixed
char buf[256];if (pkt->len > sizeof(buf)) { return -EINVAL;}memcpy(buf, pkt->data, pkt->len);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)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
- Overflow Variables and TagsCAPEC-46likelihood: High · High
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (10 more)Show less
- lists.opensuse.org/opensuse-security-announce/2019-10/msg00060.html
- lists.opensuse.org/opensuse-security-announce/2019-10/msg00061.html
- lists.debian.org/debian-lts-announce/2019/10/msg00003.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FX56KYWC7X4ETV4P6HGJC7GZUEBITBBS/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HDMZGNBLZZKAGBI2PNXYWWKLD2LXKFH6/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WI7ZENFAWCHF2RU4NHPL2CU4WGZ4BNDJ/
- seclists.org/bugtraq/2020/Jan/31
- t2.fi/schedule/2019/
- usn.ubuntu.com/4565-1/
- www.debian.org/security/2020/dsa-4607
Vendor advisories and official records. Exploit/PoC links are deliberately left out.