Security Resilience

CVE-2023-0435

Pyload ≤ 0.4.20

Public PoC
Published
22 January 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0073 53th percentile
Risk Priority 72 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-0435 is a critical-severity Excessive Attack Surface (CWE-1125) vulnerability in Pyload Pyload. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked in the top 47% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Excessive Attack Surface in GitHub repository pyload/pyload prior to 0.5.0b3.dev41.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.001 Junk Data Command And Control
Adversaries may add junk data to protocols used for command and control to make detection more difficult.
T1027.008 Stripped Payloads Stealth
Adversaries may attempt to make a payload difficult to analyze by removing symbols, strings, and other human readable information.
T1030 Data Transfer Size Limits Exfiltration
An adversary may exfiltrate data in fixed size chunks instead of whole files or limit packet sizes below certain thresholds.
T1070.006 Timestomp Stealth
Adversaries may modify file time attributes to hide new files or changes to existing files.
T1070.007 Clear Network Connection History and Configurations Stealth
Adversaries may clear or remove evidence of malicious network connections in order to clean up traces of their operations.
T1070.010 Relocate Malware Stealth
Once a payload is delivered, adversaries may reproduce copies of the same malware on the victim system to remove evidence of their presence and/or avoid defenses.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-47890Same product: Pyload Pyload
CVE-2024-47821Same product: Pyload Pyload
CVE-2024-32880Same product: Pyload Pyload
CVE-2023-0297Same product: Pyload Pyload
CVE-2026-44226Same product: Pyload Pyload
CVE-2026-41133Same product: Pyload Pyload
CVE-2023-0434Same product: Pyload Pyload
CVE-2026-35464Same product: Pyload Pyload
CVE-2023-0227Same product: Pyload Pyload
CVE-2026-40071Same product: Pyload Pyload

Affected Assets

pyload
pyload
≤ 0.4.20

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

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Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 8 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)

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Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.AM-05 partial match
blocks

Prioritization helps focus reduction efforts on high-value assets but does not itself limit the quantitative attack surface.

PR.PS-01 partial match
blocks

Hardened baselines and configuration management directly reduce unnecessary services, ports, and features that enlarge attack surface.

PR.PS-05 partial match
blocks

Restricting execution to only permitted software prevents addition of extraneous components that increase attack surface.

PR.PS-06 partial match
blocks

Secure SDLC practices explicitly include attack-surface measurement and minimization during design and implementation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

degrades

Network security controls (firewalls, segmentation, hardening) shrink the externally reachable attack surface.

degrades

Restricting network services reduces exposed interfaces, though broader attack-surface decisions may still remain.

blocks

A.8.22's network domain segregation and perimeter gateways directly reduce the attack surface by limiting exposure and controlling inter-domain traffic based on trust/criticality; the bounded remainder is internal attack surface within a single domain (or misconfigured gateways), which the clause does not reach.

blocks

Secure SDLC practices include attack-surface reduction reviews during design and release.

removes

A.8.26 only requires that security requirements (including attack-surface reduction) be identified and specified during development or acquisition; it does not itself remove the excessive attack surface from any delivered product.

blocks

A.8.27 mandates security-by-design principles (least privilege, default deny, zero-trust, attack-surface reduction via hardening and reviews) that can shrink the attack surface below the undesirable maximum, but the clause is about establishing/applying/reviewing principles rather than mandating any specific quantitative bound or guaranteeing the surface never exceeds it.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248823 OL 8 must not have the telnet-server package installed. blocks CWE-1125
  • V-248827 OL 8 must not have the rsh-server package installed. blocks CWE-1125
RHEL 7 (2 rules)
  • V-204502 The Red Hat Enterprise Linux operating system must not have the telnet-server package installed. blocks CWE-1125
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. blocks CWE-1125
RHEL 8 (1 rule)
  • V-230487 RHEL 8 must not have the telnet-server package installed. blocks CWE-1125

References