Security readout for executives and security teams
Plain-English summary
CVE-2018-16890 affects libcurl when it processes NTLM authentication responses from a malicious or faulty NTLM server. A bad length and offset combination can make libcurl read past a heap buffer. Business risk is moderate: possible information exposure or crash-like disruption, but interaction with an NTLM server is required.
Executive priority
Treat as a moderate dependency-risk cleanup item. It deserves routine patching and asset discovery, especially in environments using NTLM or embedded appliances, but the supplied evidence does not justify emergency response absent a vulnerable, exposed NTLM workflow.
Technical view
libcurl versions 7.36.0 through before 7.64.0 contain an integer overflow in ntlm_decode_type2_target in lib/vauth/ntlm.c. Incorrect validation of NTLM type-2 target data can produce a heap out-of-bounds read. CVSS 3.0 is 5.4 with network attack vector, low complexity, user interaction required, low confidentiality impact, and low availability impact.
Likely exposure
Exposure is most likely where applications, operating systems, containers, or appliances use vulnerable libcurl builds with NTLM authentication enabled. Vendor advisories from Debian, Ubuntu, Red Hat, NetApp, Siemens, and Oracle suggest dependency-level reach across packaged and embedded products.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The attack scenario requires libcurl to process a crafted NTLM type-2 message from a malicious or broken NTLM server. This limits urgency compared with unauthenticated server-side remote code execution.
Researcher notes
Focus analysis on libcurl NTLM client-side parsing. The flaw is CWE-125 and stems from integer overflow affecting target data length and offset validation. Avoid assuming all curl usage is exposed; exploitability depends on NTLM negotiation with attacker-controlled or faulty server responses.
Mitigation direction
- Upgrade curl/libcurl to a fixed vendor-supported build, such as 7.64.0 or a backported package.
- Apply relevant distribution or product advisories from Debian, Ubuntu, Red Hat, NetApp, Siemens, Oracle, or other vendors.
- Identify embedded libcurl copies in appliances, containers, and bundled third-party applications.
- Review whether NTLM authentication is needed and disable unused NTLM flows where supported.
- Monitor vendor guidance for products that ship their own libcurl rather than using the OS package.
Validation and detection
- Inventory curl and libcurl versions across servers, containers, workstations, appliances, and application bundles.
- Confirm whether vulnerable assets initiate NTLM-authenticated connections to servers outside trusted control.
- Map findings to vendor advisories because fixed versions may be backported without showing 7.64.0.
- Verify patch status through package metadata, SBOMs, or vendor release notes.
- Prioritize validation on internet-facing workflows, proxy paths, and legacy Windows authentication integrations.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-125: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2018-16890 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.4 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L2.82.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
5.4MediumVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
Source materials
- CVE List V5 sourceCVE List V5
- DSA-4386CVE reference · vendor-advisory, x_refsource_DEBIAN
- https://curl.haxx.se/docs/CVE-2018-16890.htmlCVE reference · x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20190315-0001/CVE reference · x_refsource_CONFIRM
- USN-3882-1CVE reference · vendor-advisory, x_refsource_UBUNTU
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16890CVE reference · x_refsource_CONFIRM
- [infra-devnull] 20190404 [GitHub] [incubator-openwhisk-runtime-ballerina] falkzoll commented on issue #15: Update to new base image jdk8u202-b08_openj9-0.12.1.CVE reference · mailing-list, x_refsource_MLIST
- https://cert-portal.siemens.com/productcert/pdf/ssa-436177.pdfCVE reference · x_refsource_CONFIRM
- https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.htmlCVE reference · x_refsource_MISC
- https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.htmlCVE reference · x_refsource_MISC
- https://support.f5.com/csp/article/K03314397?utm_source=f5support&%3Butm_medium=RSSCVE reference · x_refsource_CONFIRM
- RHSA-2019:3701CVE reference · vendor-advisory, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.