Description
DBI versions before 1.652 for Perl allow a heap out-of-bounds write on 32-bit perl via an integer wraparound in the output buffer size computed by preparse.

preparse reserves its output buffer with `newSV(strlen(statement) * 7 + 16)`, budgeting seven output bytes per input byte for the longest ':p99999' expansion. The product is computed in STRLEN, which is 32 bits wide on a 32-bit perl build, so a statement of 613,566,757 bytes multiplies to 4,294,967,299, wraps modulo 2^32 to 3, and reserves 19 bytes. The parser then copies the statement out through a raw pointer with no capacity check, writing the whole 585 MB input past the end of the allocation. The 99,999 placeholder limit does not bound this path, which is reached by ordinary non-placeholder content.

Any caller that passes an untrusted statement of that length to preparse on a 32-bit perl gets a heap out-of-bounds write of attacker controlled bytes. Builds with a 64-bit STRLEN are not affected, since the wrap there needs a statement of about 2.3 exabytes.
Published: 2026-08-15
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

DBI versions prior to 1.652 on 32‑bit Perl compute the preparse output buffer size with a 32‑bit integer, allowing a wraparound on a statement of 613,566,757 bytes. This results in a buffer allocated only 19 bytes in size yet a 585 MB string is copied into it, overwriting heap memory with attacker controlled data. The vulnerability arises from an integer overflow (CWE‑190) followed by an out‑of‑bounds write (CWE‑787). If an attacker can supply such a large statement to preparse, the overflow can corrupt heap structures or inject malicious payloads, leading to loss of integrity or arbitrary code execution.

Affected Systems

The flaw affects Perl DBI module versions earlier than 1.652 running on 32‑bit Perl interpreters. Operations that accept untrusted SQL statements on such builds are vulnerable; 64‑bit Perl builds are not impacted because the 32‑bit STRLEN wraparound does not occur.

Risk and Exploitability

The flaw is limited to 32‑bit Perl builds; 64‑bit builds would require an impractically large statement to trigger the wraparound. The exploitation probability is unknown due to lack of EPSS data, and the vulnerability is not listed in CISA KEV. Nonetheless, the high potential for code execution and the fact that a single oversized SQL command can trigger the issue make it an attractive local or remote code‑execution opportunity wherever untrusted SQL is processed.

Generated by OpenCVE AI on August 15, 2026 at 16:28 UTC.

Remediation

Vendor Solution

Upgrade to DBI 1.652 or later.


Vendor Workaround

On 32-bit depoyments that cannot be upgraded, limit the size of SQL statements under 292 megabytes.


OpenCVE Recommended Actions

  • Upgrade the Perl DBI module to version 1.652 or later
  • On 32‑bit deployments that cannot be upgraded, enforce a maximum SQL statement size of less than 292 MB
  • Validate and limit input SQL lengths before passing them to preparse
  • Consider switching to a 64‑bit Perl interpreter to eliminate the 32‑bit integer wraparound

Generated by OpenCVE AI on August 15, 2026 at 16:28 UTC.

Tracking

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History

Sat, 15 Aug 2026 12:30:00 +0000

Type Values Removed Values Added
Description DBI versions before 1.652 for Perl allow a heap out-of-bounds write on 32-bit perl via an integer wraparound in the output buffer size computed by preparse. preparse reserves its output buffer with `newSV(strlen(statement) * 7 + 16)`, budgeting seven output bytes per input byte for the longest ':p99999' expansion. The product is computed in STRLEN, which is 32 bits wide on a 32-bit perl build, so a statement of 613,566,757 bytes multiplies to 4,294,967,299, wraps modulo 2^32 to 3, and reserves 19 bytes. The parser then copies the statement out through a raw pointer with no capacity check, writing the whole 585 MB input past the end of the allocation. The 99,999 placeholder limit does not bound this path, which is reached by ordinary non-placeholder content. Any caller that passes an untrusted statement of that length to preparse on a 32-bit perl gets a heap out-of-bounds write of attacker controlled bytes. Builds with a 64-bit STRLEN are not affected, since the wrap there needs a statement of about 2.3 exabytes.
Title DBI versions before 1.652 for Perl allow a heap out-of-bounds write on 32-bit perl via an integer wraparound in the output buffer size computed by preparse
Weaknesses CWE-190
CWE-787
References

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: CPANSec

Published:

Updated: 2026-08-15T12:09:03.948Z

Reserved: 2026-08-11T11:58:19.137Z

Link: CVE-2026-73193

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-15T13:17:48.327

Modified: 2026-08-15T13:17:48.327

Link: CVE-2026-73193

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-15T16:30:03Z

Weaknesses