MySQL CVE-2025-50077 DoS: High Privilege Trigger Causes Server Hang

A denial-of-service weakness in the MySQL Server’s InnoDB/optimizer paths lets a high‑privileged, network‑connected actor repeatedly hang or crash the server process, causing sustained or persistent loss of availability for affected MySQL installations.

Background / Overview​

MySQL remains a cornerstone of countless web, cloud and enterprise stacks. When Oracle published its July 2025 Critical Patch Update (CPU), one of the addressed issues — cataloged under CVE-2025-50077 in public trackers — drew immediate operational attention because it permits an authenticated, high‑privilege user to trigger conditions that exhaust resources or hit unhandled error paths inside the server, resulting in hang.
The vulnerability is classified in public databases as an availability‑first issue: it does not, in its public description, disclose confidential data or provide an obvious remote code execution primitive, but it does allow attackers to deny service to applications that rely on the affected MySQL instances. Multiple independent trackers (NVD, Ubuntu, Amazon Linux, Rapid7, Snyk and others) report a consistent technical summary, affected version ranges, and a CVSS v3.1 vector that emphasizes networivileges requirement.

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What the public records say (verified facts)​

Affected components and versions​

-er — InnoDB / optimizer and stored‑procedure related code paths.

• Reease ranges: MySQL 8.0.0 through 8.0.42, 8.4.0 through 8.4.5, and 9.0.0 through 9.3.0 (inclusive).

Severity and attack model​

• CVSS v3.1 base score commonly reported: 4.9 (Medium) with vector CVSS:3./S:U/C:N/I:N/A:H — denoting network attack vector, low complexity, but high privileges required and availability impact.
• Practical exploit prerequisites: the attacker must already hold high‑privilege MySQL credentials (DBA/SUPER-equivalent or a service account with similar privo connect to the MySQL listener via one of the server’s supported protocols. This makes the flaw an insider or post‑compromise weapon for denial‑of‑service.

Impact profile​

• Primary impact: total or repeated loss of availability (mysqld hangattack stops or the service is remediated/restarted. There is no consistent public evidence that this CVE enables broad data exfiltration or arbitrary code execution in its disclosed form.

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How the bug behaves (technical summary)​

Public advisories and aggregator write-ups converge on two complementary technical characterizations:

• As an incorrect authorization / access control logic issue (CWE‑863) or a case of consumption (CWE‑400) that can be triggered by certain optimizer or stored‑procedure invocations. The exact internal trigger sequences are intentionally high‑level in vendor advisories to avoid facilitating exploitation.
• Practically, a crafted operationnt with the necessary privileges causes internal state transitions that either exhaust a limited resource or reach an unhandled error path — the result is the server process enters a hang or crashes repeatedly, producing a denial of service until stopped or remediated.

Why this matters: In modern operations, privileged credentials are frequently accessible to automation (CI/CD pipelines, backup tools, replication agents) and occasionally mismanaged. A single compromised administrative credential turns this CVE into a reliable outage vector for an adversary or---

Real‑world threat model and attack scenarios​

Different environments change the risk profile. Consider these representative scenarios:

• Multi‑tenant hosting or shared control panels: a compromised tol with elevated privileges can weaponize the flaw to deny service to other tenants.
• CI/CD and automation pipelines: service accounts used for deployments that carry elevated DDL/DDL‑adjacent privileges can be a pivot to trigger the condition from an attacker who compromises the pipeline.
• Misconfigured public endpoints: if administrative accounts are reachable from less‑trusted networks, the attacker’s path to exploitation becomes much easier. ([explore.alas.aws.amazon.com](CVE-2025-50077 exploitation requires high privileges, classic unauthenticated internet scanning is less likely to succeed unless administrative credentials are exposed or the attacker chains other vulnerabilities to obtain them. That lowers but does not eliminate exploitation likelihood — history shows credential theft and lateral movement are common in real breaches.

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Verification: what I checked and why​

To ensure readers can act with confidence, I cross‑checked the load‑bearing facts across multiple independent sources:

• The NVD entry that summarizes the CVE, affected versions and CVSS vector.
• Oracle’s Linux/Oracle vendor CVE page and CPU advisory listings that tie the flaw to the July 2025 CPU and list affected version ranges.
• Distribution advisories (Ubuntu, Amazon Linux) and vendor trackers that mapped the upstream fixes into distro packages and confirmed remediation targets.
• Independent vulnerability databases and operational guyk and Aqua Security that document attack prerequisites, detection signals, and practical remediation steps.

Where vendor advisories withheld exploit details (deliberately), I relied on cross‑referenced summaries and distribution errata that list fixed package versions to verify both scope and remediation. Multiple independ on the same affected ranges and the same operational impact, which strengthens confidence in the technical facts above.

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Detection and hunting: what defenders should look for​

Because the public disclosure ull technical PoC, defenders must rely on operational telemetry to detect exploitation attempts or successful misuse. Key indicators include:

• Repeated mymps, or repeated restarts logged by systemd/journald or container orchestrator events. Configure alerts for N restarts within M minutes.
• Correlation between crash timeive sessions: watch MySQL general logs or an audit plugin for stored‑procedure creation, ALTER/DDL or other privileged statements immediately preceding a crash.
• Unusual activity from privileged accounts:from unfamiliar IPs, sudden bursts of DDL, or scripted sequences from management tooling.
• For containerized deployments: pod restarts, liveness probe failures and repeated scheduler churn tied to MySQL containers. These can be early fleet‑scale indicators.

For forensic preservation, capture MySQL error logs, general and audit logs, binary logs, and any core dumps; copy logs before restarting services to avoid overwriting data critical to incident analysis.

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Mitigation and remediation: an operational playbefinitive fix. The vendor included the repair in its July 2025 CPU; downstream distributions have rebased packages and published errata. In practice, follow this prioritized sequence:​

• Inventory first — find every MySQL instance and confirm its exact version with:
• mysql --version
• mysql -e "SHOW VARIABLES LIKE 'version';"
  Use package manaontainer image scans to locate embedded mysqld binaries in images.
• Immediate compensations (if you cannot patch instantly):
• Restrict MySQL listeners to internal trusted networks only (firewalls, security groups, host ACLs).
• Enforce bastion/VPN for administrative conne on management hosts.
• Temporarily disable or rotate nonessential high‑privilege accounts and vault credentials.
• Patch in a controlled fashion:
• Preferred upstream fixed releases: MySQL 8.0.43, 8.4.6, and 9.4.0 (or vendor‑eqvided in downstream errata). Confirm the exact package name/version in your distro’s advisories.
• Test patches in staging with realistic workchecks.
• Patch replicas first, promote a patched replica to primary (if applicable), then update the former primary — this minimizes downtime for master‑follower topologies.
• Container and image remediation:
  do not fix container images that embed vulnerable binaries. Rebuild and redeploy images from patched base images. Use CI pipelines and SBOMs to locate and refresh vulnerable artifacts.
• Post‑patch validation:
• Confirm mysqld starts, accepts connections, and replication catches up.
• Run smoke test suitetore flows and ensure monitoring dashboards show normal operation.
• Longer‑term hardening:
• Enforce least privilege on database accounts, rotate and vault credentials, and restrict service accounts to the minimum necessary privileges.
• Centralize logs, add alerts for repeated restarts, and conduct tabletop exercises that simulate credential compromise plus database DoS.

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Patching nuances and vendor coordination​

• Downstream packaging matters: Oracle’s upstream fixes are the source of truth, but many organizations consume OS vendor packages (Debian/Ubuntu/RHEL/Oracle Linux/SUSE). Confirm that your platform’s package repos have been updated to include the patched upstream build before you mark an instance remediated. ([linux.oracle.com](linux.oracle.com | CVE-2025-50077 services may patch on their own schedule. Operators using managed services must confirm with their provider whether the service has been patched and request off‑window patching if required.
• Containerized environments: rebuilding images and redeploying is a separate operational path and must be scheduled as part of your full remediation plan. Do not assume host OS updates fix containers.

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Threat intelligence status: is there a PoC or active exploitation?​

At the time of vendor disclosure and follow‑up reporting, mainstream vendor and tracker records do not publish a widely‑trusted public proof‑of‑concept that achieves unauthenticated remote weaponization; writeups emphasize the high‑privilegreduces the immediate likelihood of mass internet exploitation. However, multiple trackers warn that the attack is easily reproducible* once the privilege barrier is crossed, so adversarie credentials — or an insider — can weaponize it rapidly. Treat the absence of a PoC as lowering but not eliminating operational urgency.
Caveat: exploit availability and in‑the‑wild activity can change rapidly. If you operate production MySQL at scale, do not rublic PoC as a reason to delay patching.

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Critical analysis — strengths in the vendor response and remaining risks​

Strengths

• Oracle published the fix as part of a scheduled, well‑documented CPU, giving downstream packagers and cloud providers a canonical patch to work from. That coordination reduces ambiguity and helps distributors ship secure packages.
• Multiple independent trackers (NVD, Ubuntu, Rapid7, Snyk, Aqua) quickly erenced the CVE, making it easier for operators to map upstream versions to distro packages and take action.

Rrational gaps

• The privilege requirement cuts both ways: it lowers mass‑scanning risk but brings the danger into environments where privileged credentials are shared broadly (automation, management too Many estates have such shared credentials.
• Container image and appliance supply‑chain inertia: images built before the CPU remain vulnerable until rebuilt and redeployed. Operators often underestimate the ifacts.
• Numerical CVSS scores (mid‑range) can underplay operational impact. A “Medium” scbusiness impact — a production database outage can be costly and must be prioritized accordical checklist (quick, actionable)
• Inventory: List every MySQL instance, container image, VM, and managed service; confirm versions with mysql --version and SHOW VARIABLES LIKE 'version'.
• Isolate: Immediately restrict network reachability of any administrative endpoints.
• Harden: Rotailege credentials; disable unused admin accounts.
• Patch: Schedule patching to vendor/repo packages that contain the fix (upstream indicators: 8.0.43, 8.4.6, 9uivalents). Test in staging; patch replicas first.
• Rebuild: Replace container images that include vulnerable binaries; redeploy.
• Monitor: Add alerts for repeated mysqld crashes and privileged DDL patterns. Collect logs and retain for at least the duration of the incident investigation.

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Final assessment and recommended priorities​

CVE‑2025‑50077 is a concrete operational threat: while it does not (as publicly described) enable data exfiltration or RCE, it lets an attacker with high privileges reliably remove database availability — a clearly highoduction services. The numerical CVSS rating (commonly reported as 4.9) understates the business consequences for critical systems where downtime is unacceptable. Cross‑referenced vendor advisories and distribution advisories provide a clear remediation iority for operators should be:

• Immediate inventory and exposure reduction (firewalling, bastion access).
• Rapid patching according to vendor and distro guidance, combined with careful staging and post‑patch validation. (rapid7.com)
• Container/CI pipeline remediations and credential governance improvements as medium‑term hardening.

Treat this CVE as urgent for any MySQL deployment that exposes administrative access beyond strictly controlled bastions or that uses shared/vaulted credentials acnes. The combination of a reproducible crash and widespread MySQL usage makes the operational cost of inaction high.

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CVE‑2025‑50077 is a reminder that availability‑focused defects in foundational infrastructure can be as destructive as data breaches; patch promptly, harden privileges, and treat detection and recovery procedures with the same rigor you apply to confidentiality risks.

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Source: MSRC Security Update Guide - Microsoft Security Response Center