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CVE-2023-4818· NVD / CVE Program· CNA CERT-PL

PAX A920 device allows to downgrade bootloader due to a bug in its version check.

PAX A920 device allows to downgrade bootloader due to a bug in its version check. The signature is correctly checked and only bootloader signed by PAX can be used.  The attacker must have physical USB access to the device in order to exploit this vulnerability.

HighCVSS 7.6 · v3.1—No exploit No fix recorded
Published
Jan 15, 2024
Updated
Jun 17, 2026
EPSS
0.7% · 50th percentile
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Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Affected systems

VendorProduct
paxtechnologypaydroid
paxtechnologya920

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • paxtechnology paydroid7.1.2_aquarius_11.1.50_20230614

Versions reported by the vendor

Affected version ranges reported by the assigning authority (CERT-PL). Independent of NVD's CPE analysis and usually ahead of it.

  • PAX Technology A920

    • before A920_AP_Boot_Release_V5.14affected

Same product

paxtechnology: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-42137PAX Android based POS devices with PayDroid_8.1.0_Sagittarius_V11.1.50_20230614 or earlier can allow for command execution with high privile
    31Monitor
  • CVE-2023-42136PAX Android based POS devices with PayDroid_8.1.0_Sagittarius_V11.1.50_20230614 or earlier can allow the execution of arbitrary commands wit
    31Monitor
  • CVE-2022-26582PAX A930 device with PayDroid_7.1.1_Virgo_V04.3.26T1_20210419 can allow an attacker to gain root access through command injection in systool
    31Monitor
  • CVE-2022-26580PAX A930 device with PayDroid_7.1.1_Virgo_V04.3.26T1_20210419 can allow the execution of specific command injections on selected binaries in
    28Monitor
  • CVE-2023-42135PAX A920Pro/A50 devices with PayDroid_8.1.0_Sagittarius_V11.1.50_20230614 or earlier can allow local code execution via parameter injection
    27Monitor
  • CVE-2023-42134PAX Android based POS devices with PayDroid_8.1.0_Sagittarius_V11.1.45_20230314 or earlier can allow the signed partition overwrite and subs
    27Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2023-421350 days apartPAX A920Pro/A50 devices with PayDroid_8.1.0_Sagittarius_V11.1.50_20230614 or earlier can allow local code execution via parameter injection
    27Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Physical access to the device is required.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Physical
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVSS vector

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records