CVE-2017-8816

The NTLM authentication feature in curl and libcurl before 7.57.0 on 32-bit platforms allows attackers to cause a denial of service (integer overflow and resultant buffer overflow, and application crash) or possibly have unspecified other impact via vectors involving long user and password fields.

Published: 2017-11-29 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-8816 is rated High Risk (77.2/100): CVSS Critical severity, with high exploitation likelihood (EPSS 8.52%, 94th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +8.07% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-8816

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.45% 8.52% +8.07%
2 2026-04-01 0.44% 0.45% +0.02%
3 2026-03-04 — 0.44% —

Full EPSS history (42 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-8816

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2017-8816

OS Trackers for CVE-2017-8816

vendor priority summary link
alpine — CVE-2017-8816: 1 source package rows (curl); 60 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 50. https://security.alpinelinux.org/vuln/CVE-2017-8816
debian not yet assigned CVE-2017-8816 not yet assigned priority: Debian including 1 source packages (curl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-8816
gentoo normal CVE-2017-8816: 1 GLSA(s) (201712-04), 1 atom(s) (net-misc/curl); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2017-8816
redhat medium — https://access.redhat.com/security/cve/CVE-2017-8816
suse medium CVE-2017-8816 severity moderate: SUSE including 319 source package names (0.9.1:libcurl4-7.37.0-37.11.3, 1.0.0:libcurl4-7.37.0-37.11.3, …), 414 product×package rows across 77 product lines (Container caasp/v4/default-http-backend, Container caasp/v4/dnsmasq-nanny, … (77 product lines)): Fixed 199, Known Affected 157, Known Not Affected 58. https://www.suse.com/security/cve/CVE-2017-8816/
ubuntu medium CVE-2017-8816 medium priority: Ubuntu including 1 source packages (curl), 5 status rows across 5 suites (artful, trusty, upstream, xenial, zesty): released 3, needs-triage 1, not-affected 1. https://ubuntu.com/security/CVE-2017-8816

Affected software / configurations for CVE-2017-8816

Vendor Product Version Raw CPE
haxx curl > 7.36.0, <= 7.56.1 cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*
haxx libcurl >= 7.36.0, <= 7.56.1 cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2017-8816

cvelogic Threat Intelligence