CVE-2020-10933

Exp

An issue was discovered in Ruby 2.5.x through 2.5.7, 2.6.x through 2.6.5, and 2.7.0. If a victim calls BasicSocket#read_nonblock(requested_size, buffer, exception: false), the method resizes the buffer to fit the requested size, but no data is copied. Thus, the buffer string provides the previous value of the heap. This may expose possibly sensitive data from the interpreter.

Published: 2020-05-04 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-10933 is rated High Exploit Risk (65.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.56%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2020-10933

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-10933

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 2026-06-19 2.51% 2.56% +0.05%
2 2026-06-15 0.44% 2.51% +2.08%
3 2026-02-17 — 0.44% —

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-10933

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N 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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N 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:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-10933

OS Trackers for CVE-2020-10933

vendor priority summary link
alpine medium CVE-2020-10933: 1 source package rows (ruby); 10 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 0. https://security.alpinelinux.org/vuln/CVE-2020-10933
debian not yet assigned CVE-2020-10933 not yet assigned priority: Debian including 1 source packages (ruby2.7), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2020-10933
redhat medium — https://access.redhat.com/security/cve/CVE-2020-10933
suse medium CVE-2020-10933 severity moderate: SUSE including 357 source package names (2.17-17.3:libruby2_5-2_5-2.5.8-4.11.1, 2.17-17.3:ruby2.5-2.5.8-4.11.1, …), 968 product×package rows across 221 product lines (Container bci/ruby, Container suse/rmt-server, … (221 product lines)): Fixed 769, Known Affected 157, Known Not Affected 42. https://www.suse.com/security/cve/CVE-2020-10933/
ubuntu low CVE-2020-10933 low priority: Ubuntu including 5 source packages (ruby1.9.1, ruby2.0, ruby2.3, ruby2.5, ruby2.7), 35 status rows across 7 suites (bionic, eoan, focal, groovy, trusty, upstream, xenial): DNE 25, needs-triage 4, released 3, not-affected 2, ignored 1. https://ubuntu.com/security/CVE-2020-10933

Affected software / configurations for CVE-2020-10933

Vendor Product Version Raw CPE
ruby-lang ruby >= 2.5.0, <= 2.5.7 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby >= 2.6.0, <= 2.6.5 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby 2.7.0 cpe:2.3:a:ruby-lang:ruby:2.7.0:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2020-10933

cvelogic Threat Intelligence