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NVD / CVE Program· CNA certcc

CVE-2011-0420: The grapheme_extract function in the Internationalization extension (Intl) for ICU for PHP 5.3.5 allows context-dependent attackers to cause…

MediumCVSS 5.0 · v2.0—Proof of concept Fix available

Noroxi assessment

Priority: Monitor (action score 24/100)

  • Public proof-of-concept code exists (Exploit-DB); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 14.4% (FIRST EPSS); higher than 96.6% of all records.
  • No special conditions are required; it is repeatable.
  • Fixed version: php5 (Debian:5.0) 5.2.6.dfsg.1-1+lenny12; php5 (Debian:6.0) 5.3.3-7+squeeze3; php5 (openSUSE:Tumbleweed) 5.6.28-1.1.

Low priority for now. Upgrade to php5 (Debian:5.0) 5.2.6.dfsg.1-1+lenny12; php5 (Debian:6.0) 5.3.3-7+squeeze3; php5 (openSUSE:Tumbleweed) 5.6.28-1.1 or later.

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

The grapheme_extract function in the Internationalization extension (Intl) for ICU for PHP 5.3.5 allows context-dependent attackers to cause a denial of service (crash) via an invalid size argument, which triggers a NULL pointer dereference.

Published
Feb 18, 2011
Updated
Jun 16, 2026
EPSS
14.4% · 96th percentile
CWE
—

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
20 / 40 · 5.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
4 / 30 · 14.4%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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

Follow CVE-2011-0420

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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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

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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 php5.3.5

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:5.0php5before 5.2.6.dfsg.1-1+lenny125.2.6.dfsg.1-1+lenny12
Debian:6.0php5before 5.3.3-7+squeeze35.3.3-7+squeeze3
openSUSE:Tumbleweedphp5before 5.6.28-1.15.6.28-1.1
openSUSE:Tumbleweedphp7before 7.0.14-1.47.0.14-1.4

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-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
  • ← EarlierCVE-2011-0755Feb 2, 2011 · Integer overflow in the mt_rand function in PHP before 5.3.4 might make it easier for context-dependent attackers to predict the return…
    21Monitor
  • Later →CVE-2011-1092Mar 15, 2011 · Integer overflow in ext/shmop/shmop.c in PHP before 5.3.6 allows context-dependent attackers to cause a denial of service (crash) and…
    35Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:php55.2.6.dfsg.1-1+lenny12 · Debian:5.0Package registry (OSV)
opensuse:php55.6.28-1.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:php77.0.14-1.4 · openSUSE:TumbleweedPackage registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Exploit-DB entry ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Exploit-DB entrydos2011-02-17
Exploit-DB entrydos2011-02-17

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.

  1. First PoC-2 d
  2. Published
  3. TodayNov 15, 2026+5749 d

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

  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

—

CVSS vector

AV:N/AC:L/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.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (8 more)

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

All records