Description
An integer overflow in the mtar_next function in src/microtar.c in rxi microtar 0.1.0 allows a remote attacker to cause a denial of service (uncontrolled CPU consumption / infinite loop) via a crafted tar archive. mtar_next computes the offset to the next record as round_up(h.size, 512) + sizeof(mtar_raw_header_t) using 32-bit arithmetic.
Published: 2026-06-17
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

An integer overflow occurs in mtar_next() of rxi/microtar 0.1.0, where the function computes the next offset using 32‑bit arithmetic. A malicious tar archive that causes the offset calculation to wrap around makes the program enter an infinite loop, consuming CPU until it is terminated. The flaw is a classic integer overflow (CWE‑190) combined with uncontrolled looping (CWE‑835), resulting in a denial‑of‑service condition.

Affected Systems

The vulnerable product is rxi/microtar 0.1.0. The integer overflow exists in the src/microtar.c file of this version, affecting any installation that processes tar archives with this library.

Risk and Exploitability

The CVSS score of 8.7 indicates a high severity vulnerability. The EPSS score is less than 1 %, suggesting a low probability of exploitation in the wild. It is not listed in CISA KEV. The likely attack vector is remote, via a malicious tar file supplied to a service that uses microtar for extraction. Supply of such a crafted archive causes the function to enter an infinite loop, producing a denial‑of‑service.

Generated by OpenCVE AI on August 10, 2026 at 23:24 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade microtar to a patched version that removes the integer overflow in mtar_next()
  • If an upgrade is not possible, only process tar archives that originate from trusted sources or implement pre‑processing checks to reject files with header sizes in the vulnerable range
  • Add defensive validation in the code to detect overflow or limit the size of individual entries before the offset calculation

Generated by OpenCVE AI on August 10, 2026 at 23:24 UTC.

Tracking

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Advisories

No advisories yet.

History

Mon, 10 Aug 2026 12:00:00 +0000

Type Values Removed Values Added
Description An integer overflow in the mtar_next() function in src/microtar.c in rxi microtar 0.1.0 allows a remote attacker to cause a denial of service (uncontrolled CPU consumption / infinite loop) via a crafted tar archive. mtar_next() computes the offset to the next record as round_up(h.size, 512) + sizeof(mtar_raw_header_t) using 32-bit arithmetic. When the header size field is a multiple of 512 in the range 0xFFFFFC01-0xFFFFFE00 (e.g. 0xFFFFFE00), the addition wraps to 0, so mtar_next() seeks to the current record position instead of advancing. As a result, mtar_find() and any loop that iterates entries with mtar_next() repeat indefinitely over the same record, hanging the process at 100% CPU with no recovery. An integer overflow in the mtar_next function in src/microtar.c in rxi microtar 0.1.0 allows a remote attacker to cause a denial of service (uncontrolled CPU consumption / infinite loop) via a crafted tar archive. mtar_next computes the offset to the next record as round_up(h.size, 512) + sizeof(mtar_raw_header_t) using 32-bit arithmetic.
Title rxi microtar - Integer Overflow in mtar_next() Causes Infinite Loop DoS Integer Overflow in rxi/microtar mtar_next() Causes Infinite Loop DoS

Mon, 10 Aug 2026 11:45:00 +0000

Type Values Removed Values Added
Title Integer Overflow in rxi/microtar mtar_next() Causes Infinite Loop DoS rxi microtar - Integer Overflow in mtar_next() Causes Infinite Loop DoS

Thu, 18 Jun 2026 04:45:00 +0000

Type Values Removed Values Added
First Time appeared Rxi
Rxi microtar
Vendors & Products Rxi
Rxi microtar
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Wed, 17 Jun 2026 14:00:00 +0000

Type Values Removed Values Added
Description An integer overflow in the mtar_next() function in src/microtar.c in rxi microtar 0.1.0 allows a remote attacker to cause a denial of service (uncontrolled CPU consumption / infinite loop) via a crafted tar archive. mtar_next() computes the offset to the next record as round_up(h.size, 512) + sizeof(mtar_raw_header_t) using 32-bit arithmetic. When the header size field is a multiple of 512 in the range 0xFFFFFC01-0xFFFFFE00 (e.g. 0xFFFFFE00), the addition wraps to 0, so mtar_next() seeks to the current record position instead of advancing. As a result, mtar_find() and any loop that iterates entries with mtar_next() repeat indefinitely over the same record, hanging the process at 100% CPU with no recovery.
Title Integer Overflow in rxi/microtar mtar_next() Causes Infinite Loop DoS
Weaknesses CWE-190
CWE-835
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

Rxi Microtar
cve-icon MITRE

Status: PUBLISHED

Assigner: TuranSec

Published:

Updated: 2026-08-10T11:44:08.688Z

Reserved: 2026-06-13T16:39:46.122Z

Link: CVE-2026-54417

cve-icon Vulnrichment

Updated: 2026-06-17T15:01:31.811Z

cve-icon NVD

Status : Deferred

Published: 2026-06-17T14:17:58.540

Modified: 2026-08-10T12:17:17.957

Link: CVE-2026-54417

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-10T23:30:07Z

Weaknesses
  • CWE-190

    Integer Overflow or Wraparound

  • CWE-835

    Loop with Unreachable Exit Condition ('Infinite Loop')