CVE-2021-22557Public exploit

Local code execution via unsafe YAML loading

Published Oct 4, 2021 · Updated Aug 3, 2024

Code injection in Google SLO Generator 2.0.0 and earlier allows local users to execute code through a crafted YAML migration file. The migrate command passes backend configuration to PyYAML's unsafe yaml.Loader, which constructs Python object tags that invoke os.system. Local access sufficient to run the CLI and select the crafted file is required, and resulting commands execute with the SLO Generator process's privileges.

CVSS severity5.3
Medium
EPSS probability1.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in Google SLO Generator 2.0.0 and earlier allows local users to execute code through a crafted YAML migration file. The migrate command passes backend configuration to PyYAML's unsafe yaml.Loader, which constructs Python object tags that invoke os.system. Local access sufficient to run the CLI and select the crafted file is required, and resulting commands execute with the SLO Generator process's privileges.

The record

CVE
CVE-2021-22557
Published
Oct 4, 2021
Updated
Aug 3, 2024
Vendor
Google
Product
SLO Generator
Classifications
CWE-94, CWE-78, T1059
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=2.0.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google · SLO Generatorversion=unspecified <=2.0.0

Published CVSS scores

5.3GoogleCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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