CVE-2016-7434: The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (crash) via a crafted mrulist query.
Noroxi assessment
Priority: Plan (action score 46/100)
- Public proof-of-concept code exists (Exploit-DB, GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 53% (FIRST EPSS); higher than 98.9% 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: ntp (Debian:11) 1:4.2.8p9+dfsg-1; ntp (SUSE:Linux Enterprise Desktop 12 SP1) 4.2.8p9-55.1; ntp (SUSE:Linux Enterprise Server 11 SP4) 4.2.8p9-57.2.
Add it to your regular patch cycle. Upgrade to ntp (Debian:11) 1:4.2.8p9+dfsg-1; ntp (SUSE:Linux Enterprise Desktop 12 SP1) 4.2.8p9-55.1; ntp (SUSE:Linux Enterprise Server 11 SP4) 4.2.8p9-57.2 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
- Published
- Jan 13, 2017
- Updated
- Jun 16, 2026
- EPSS
- 53.0% · 98th percentile
- CWE
- CWE-20
Report tools
Action score
46
Add it to your regular patch cycle.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 16 / 30 · 53.0%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi 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.
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- ntp ntp4.3.0 and later · before 4.3.94
- ntp ntp4.2.7
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:11 | ntp | before 1:4.2.8p9+dfsg-1 | 1:4.2.8p9+dfsg-1 |
| SUSE:Linux Enterprise Desktop 12 SP1 | ntp | before 4.2.8p9-55.1 | 4.2.8p9-55.1 |
| SUSE:Linux Enterprise Server 11 SP4 | ntp | before 4.2.8p9-57.2 | 4.2.8p9-57.2 |
| SUSE:Linux Enterprise Server for SAP Applications 12 | ntp | before 4.2.8p9-46.18.1 | 4.2.8p9-46.18.1 |
| SUSE:OpenStack Cloud 5 | ntp | before 4.2.8p9-48.9.1 | 4.2.8p9-48.9.1 |
Same product
ntp: all recordsOther highest-scoring records for the same primary product.
- CVE-2015-7871Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to bypass authentication.64This week
- CVE-2014-9295Multiple stack-based buffer overflows in ntpd in NTP before 4.2.8 allow remote attackers to execute arbitrary code via a crafted packet…54Plan
- CVE-2013-5211The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service (traffic…49Plan
Published before and after this one in the same product
- ← EarlierCVE-2016-7431Jan 13, 2017 · NTP before 4.2.8p9 allows remote attackers to bypass the origin timestamp protection mechanism via an origin timestamp of zero.24Monitor
- ← EarlierCVE-2016-7433Jan 13, 2017 · NTP before 4.2.8p9 does not properly perform the initial sync calculations, which allows remote attackers to unspecified impact via unknown…24Monitor
- Later →CVE-2016-9310Jan 13, 2017 · The control mode (mode 6) functionality in ntpd in NTP before 4.2.8p9 allows remote attackers to set or unset traps via a crafted control…29Monitor
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:ntp | 1:4.2.8p9+dfsg-1 · Debian:11 | Package registry (OSV) |
| suse:ntp | 4.2.8p9-57.2 · SUSE:Linux Enterprise Server 11 SP4 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Exploit-DB entry ×1
- Proof-of-concept repository on GitHub ×3
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | 3 repositories | 2016-11-22 → 2019-01-06 |
| Exploit-DB entry | dos | 2016-11-21 |
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.
- First PoC-54 d
- Published
- TodayNov 15, 2026+3593 d
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate.
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
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (8 more)Show less
- support.ntp.org/bin/view/Main/NtpBug3082
- support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
- www.securityfocus.com/bid/94448
- www.securitytracker.com/id/1037354
- bto.bluecoat.com/security-advisory/sa139
- h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03706en_us
- security.FreeBSD.org/advisories/FreeBSD-SA-16:39.ntp.asc
- www.kb.cert.org/vuls/id/633847
Vendor advisories and official records. Exploit/PoC links are deliberately left out.