Ubuntu LinuxOperating system · Canonical
CVE-2019-3822
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedlibcurl versions from 7.36.0 to before 7.64.0 are vulnerable to a stack-based buffer overflow. The function creating an outgoing NTLM type-3 header (`lib/vauth/ntlm.c:Curl_auth_create_ntlm_type3_message()`), generates the request HTTP header contents based on previously received data. The check that exists to prevent the local buffer from getting overflowed is implemented wrongly (using unsigned math) and as such it does not prevent the overflow from happening. This output data can grow larger than the local buffer if very large 'nt response' data is extracted from a previous NTLMv2 header provided by the malicious or broken HTTP server. Such a 'large value' needs to be around 1000 bytes or more. The actual payload data copied to the target buffer comes from the NTLMv2 type-2 response header.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisData overflows a fixed-size buffer allocated on the stack, overwriting adjacent stack memory — including saved return addresses — which is the classic route to redirecting execution into attacker-supplied code. Crafted input is all it takes. Remediation is strict length checks, safe bounded string and memory functions, and modern stack-protection mitigations.
General guidance for the stack-based buffer overflow class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Ubuntu LinuxOperating system
= 14.04= 16.04= 18.04= 18.10
Debian LinuxOperating system
= 9.0
HTTP ServerWeb server / proxy
= 12.2.1.3.0
Enterprise LinuxOperating system
= 8.0>= 7.36.0, < 7.64.0>= 7.3>= 9.5all versionsall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped7.64.0
libcurl 7.64.0 or later
- 1. Identify all systems running libcurl versions 7.36.0 through 7.63.x: run `curl --version` or check package version with `dpkg -l | grep libcurl` (Debian/Ubuntu) or `rpm -qa | grep libcurl` (RHEL/CentOS)
- 2. For Ubuntu/Debian systems: run `sudo apt-get update && sudo apt-get install libcurl4` to upgrade to the latest available version (7.64.0 or later in most repositories)
- 3. For RHEL/CentOS/Enterprise Linux 8: run `sudo dnf update libcurl` or `sudo yum update libcurl`
- 4. After upgrading, verify the new version: `curl --version` and confirm it shows version 7.64.0 or later
- 5. Restart any applications or services that use libcurl (e.g., web servers, curl-based scripts, HTTP clients) to ensure they load the updated library
- 6. For embedded systems or appliances (NetApp Oncommand Insight, Active IQ Unified Manager, Siemens products), apply vendor-specific patches as listed in respective advisories
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-3822 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sources- bugzilla.redhat.com
- bugzilla.redhat.com
- bugzilla.redhat.com
- curl.haxx.se
- security.netapp.com
- www.oracle.com
- www.oracle.com
- www.securityfocus.com
- access.redhat.com
- cert-portal.siemens.com
- security.gentoo.org
- security.netapp.com
- support.f5.com
- usn.ubuntu.com
- www.debian.org
- lists.apache.org
- support.f5.com
- nvd.nist.gov
Practitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-3822 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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