CVE-2016-9379: citrix xenserver Improper Input Validation
Vulnerability summary
CVE-2016-9379 is a high (CVSS 7.9) Improper Input Validation vulnerability in citrix xenserver. EPSS estimates a 0.44% chance of exploitation in the next 30 days, higher than 38% of scored vulnerabilities.
Not severe (CVSS 7.9, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 10 · Related 7Timeline
- 23-01-2017PublishedVulnerability first disclosed.
- 06-08-2024Last modifiedVulnerability information updated.
Description
The pygrub boot loader emulator in Xen, when S-expression output format is requested, allows local pygrub-using guest OS administrators to read or delete arbitrary files on the host via string quotes and S-expressions in the bootloader configuration file.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated7.9HighCVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
- OSV · UbuntuEcosystem advisory · calculated7.9HighCVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
- OSV · DebianEcosystem advisory · calculated7.9HighCVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
EPSS trend
Probability
0.44%
Chance of exploitation in the next 30 days
Percentile
38%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.44% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, administrative account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Alpine1 product
- xen< 4.7.1-r1
Citrix1 product
- xenserver6.0.2 | 6.2.0 | 6.5 | 7.0
Debian1 product
- xen< 4.8.0-1
Ubuntu1 product
- xen< 4.4.2-0ubuntu0.14.04.9 | < 4.6.0-1ubuntu4.3
4 vendors · 4 products
