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NVD / CVE Program· CNA mitre

CVE-2011-0753: Race condition in the PCNTL extension in PHP before 5.3.4, when a user-defined signal handler exists, might allow context-dependent…

MediumCVSS 4.3 · v2.0—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 17/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.80% (FIRST EPSS); higher than 57.1% of all records.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Race condition in the PCNTL extension in PHP before 5.3.4, when a user-defined signal handler exists, might allow context-dependent attackers to cause a denial of service (memory corruption) via a large number of concurrent signals.

Published
Feb 2, 2011
Updated
Jun 16, 2026
EPSS
0.8% · 57th percentile

Report tools

JSON

Action score

17

Monitor

Low priority for now.

CVSS
17 / 40 · 4.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.8%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2011-0753

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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  • Uptime monitoring: 1 site, instant email when it goes down
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  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
phpphp

Using php? Add it to your stack and be the first to know about CVEs like this one. (PHP)

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When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or is weaponized

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every Monday

Affected versions

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

  • php phpup to 5.3.3 inclusive
  • php php1.0
  • php php2.0
  • php php2.0b10
  • php php3.0
  • php php3.0.1
  • php php3.0.10
  • php php3.0.11
+12 more rows
  • php php3.0.12
  • php php3.0.13
  • php php3.0.14
  • php php3.0.15
  • php php3.0.16
  • php php3.0.17
  • php php3.0.18
  • php php3.0.2
  • php php3.0.3
  • php php3.0.4
  • php php3.0.5
  • php php3.0.6

Same product

php: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-4577Argument Injection in PHP-CGIKEV
    99Now
  • CVE-2019-11043Underflow in PHP-FPM can lead to RCEKEV
    99Now
  • CVE-2012-1823sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI script (aka php-cgi), does not properly handle…KEV
    99Now

Published before and after this one in the same product

  • ← EarlierCVE-2010-4700Jan 18, 2011 · The set_magic_quotes_runtime function in PHP 5.3.2 and 5.3.3, when the MySQLi extension is used, does not properly interact with use of the…
    27Monitor
  • ← EarlierCVE-2011-0752Feb 2, 2011 · The extract function in PHP before 5.2.15 does not prevent use of the EXTR_OVERWRITE parameter to overwrite (1) the GLOBALS superglobal…
    20Monitor
  • Later →CVE-2011-0754Feb 2, 2011 · The SplFileInfo::getType function in the Standard PHP Library (SPL) extension in PHP before 5.3.4 on Windows does not properly detect…
    17Monitor

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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

    If successful

    Confidentiality
    none
    Integrity
    none
    Availability
    P · the service can be disrupted
    Attack complexity
    M
    Confidentiality impact
    None
    Integrity impact
    None
    Availability impact
    P

    Weakness class (CWE)

    CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

    CVSS vector

    AV:N/AC:M/Au:N/C:N/I:N/A:P

    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.

    ATT&CK techniques

    —

    References

    Show all references (3 more)

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

    All records