CVE-2022-31015 | Uncaught Exception (due to a data race) leads to process termination in Waitress

Exp

Waitress is a Web Server Gateway Interface server for Python 2 and 3. Waitress versions 2.1.0 and 2.1.1 may terminate early due to a thread closing a socket while the main thread is about to call select(). This will lead to the main thread raising an exception that is not handled and then causing the entire application to be killed. This issue has been fixed in Waitress 2.1.2 by no longer allowing the WSGI thread to close the socket. Instead, that is always delegated to the main thread. There is no work-around for this issue. However, users using waitress behind a reverse proxy server are less likely to have issues if the reverse proxy always reads the full response.

Published: 2022-05-31 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-31015 is rated High Exploit Risk (64.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.48%). 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-2022-31015

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

Exploit prediction scoring system (EPSS) score for CVE-2022-31015

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 2026-05-31 0.14% 0.48% +0.34%
2 2025-11-21 0.46% 0.14% -0.32%
3 2025-11-18 — 0.46% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-31015

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:L)
A normal user session is enough; they don’t have to be admin.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2022-31015

GitHub Security Advisory for CVE-2022-31015

GHSA-f5x9-8jwc-25rw · Severity: high · Ecosystem: pip — Uncaught Exception (due to a data race) leads to process termination in Waitress

OS Trackers for CVE-2022-31015

vendor priority summary link
alpine medium CVE-2022-31015: 1 source package rows (py3-waitress); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2022-31015
debian unimportant CVE-2022-31015 unimportant priority: Debian including 1 source packages (waitress), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-31015
redhat low — https://access.redhat.com/security/cve/CVE-2022-31015
suse medium CVE-2022-31015 severity moderate: SUSE including 12 source package names (python-waitress, python3-waitress, …), 51 product×package rows across 30 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (30 product lines)): Known Not Affected 41, Fixed 10. https://www.suse.com/security/cve/CVE-2022-31015/
ubuntu medium CVE-2022-31015 medium priority: Ubuntu including 1 source packages (waitress), 7 status rows across 7 suites (bionic, focal, impish, jammy, kinetic, upstream, xenial): not-affected 4, ignored 1, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2022-31015

Affected software / configurations for CVE-2022-31015

Vendor Product Version Raw CPE
agendaless waitress >= 2.1.0, < 2.1.2 cpe:2.3:a:agendaless:waitress:*:*:*:*:*:*:*:*

References for CVE-2022-31015

cvelogic Threat Intelligence