CVE-2020-15566: debian debian_linux
Vulnerability summary
CVE-2020-15566 is a medium (CVSS 6.5) vulnerability in debian debian_linux. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 35.2% of scored vulnerabilities.
Not severe (CVSS 6.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 10 · Related 9Timeline
- 07-07-2020PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a host OS crash because of incorrect error handling in event-channel port allocation. The allocation of an event-channel port may fail for multiple reasons: (1) port is already in use, (2) the memory allocation failed, or (3) the port we try to allocate is higher than what is supported by the ABI (e.g., 2L or FIFO) used by the guest or the limit set by an administrator (max_event_channels in xl cfg). Due to the missing error checks, only (1) will be considered an error. All the other cases will provide a valid port and will result in a crash when trying to access the event channel. When the administrator configured a guest to allow more than 1023 event channels, that guest may be able to crash the host. When Xen is out-of-memory, allocation of new event channels will result in crashing the host rather than reporting an error. Xen versions 4.10 and later are affected. All architectures are affected. The default configuration, when guests are created with xl/libxl, is not vulnerable, because of the default event-channel limit.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
EPSS trend
Probability
0.41%
Chance of exploitation in the next 30 days
Percentile
35%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.41% 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, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- xen< 4.11.4+24-gddaaccbbab-1
- debian_linuxEOL10.0
Alpine1 product
- xen≥ 4.10.0, < 4.12.3-r2 | ≥ 4.10.0, < 4.13.1-r2 | ≥ 4.10.0, < 4.13.1-r4 | ≥ 4.10.0, < 4.11.4-r0
Ubuntu1 product
- xen< 4.11.3+24-g14b62ab3e5-1ubuntu2.3
Xen1 product
- xen≥ 4.10.0, ≤ 4.13.1
4 vendors · 5 products
References
14 links- www.openwall.com/lists/oss-security/2020/07/07/2Mailing ListX Refsource MLISTREPORTThird Party Advisory
