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CVE-2009-1897

Status: ModifiedMedium (6.9)—Exploit
Severity6.9Medium · CVSS 2.0
Exploitation probability1.52 %higher than 74% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitAvailablePublished on Exploit-DB

The tun_chr_poll function in drivers/net/tun.c in the tun subsystem in the Linux kernel 2.6.30 and 2.6.30.1, when the -fno-delete-null-pointer-checks gcc option is omitted, allows local users to gain privileges via vectors involving a NULL pointer dereference and an mmap of /dev/net/tun, a different vulnerability than CVE-2009-1894.

CVSS

Base score
6.9
Version
2.0
Vector
AV:L/AC:M/Au:N/C:C/I:C/A:C

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
1.52 %
Percentile among all scored CVEs
74
Score date
10/21/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Public exploits

Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.

Affected technologies (1)

Linux — Linux Kernel

CWEs

References

Show 26 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2009-1897",
  "cveTags": [],
  "metrics": {
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        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
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          "baseScore": 6.9,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:M/Au:N/C:C/I:C/A:C",
          "authentication": "NONE",
          "integrityImpact": "COMPLETE",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "COMPLETE",
          "confidentialityImpact": "COMPLETE"
        },
        "acInsufInfo": false,
        "impactScore": 10,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.4,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ]
  },
  "affected": [
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      "affectedData": [
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          "vendor": "n/a",
          "product": "n/a",
          "versions": [
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              "status": "affected",
              "version": "n/a"
            }
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        }
      ]
    }
  ],
  "published": "2009-07-20T17:30:54.733",
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    {
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    },
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      "url": "http://www.openwall.com/lists/oss-security/2009/07/17/1",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
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      "tags": [
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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    {
      "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/51803",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
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    {
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-119"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The tun_chr_poll function in drivers/net/tun.c in the tun subsystem in the Linux kernel 2.6.30 and 2.6.30.1, when the -fno-delete-null-pointer-checks gcc option is omitted, allows local users to gain privileges via vectors involving a NULL pointer dereference and an mmap of /dev/net/tun, a different vulnerability than CVE-2009-1894."
    },
    {
      "lang": "es",
      "value": "La función tun_chr_poll en drivers/net/tun.c en el subsistema tun del kernel de Linux v2.6.30 y v2.6.30.1, cuando se omite la opción -fno-delete-null-pointer-checks en gcc, permite a atacantes locales obtener privilegios a través de vectores que implican desreferenciacion de punteros NULL y un nmap de /dev/net/tun, es una vulnerabilidad diferente a CVE-2009-1894."
    }
  ],
  "lastModified": "2026-06-16T23:08:18.753",
  "configurations": [
    {
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  "vendorComments": [
    {
      "comment": "Red Hat is aware of this issue and is tracking it via the following bug:\nhttps://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=CVE-2009-1897\n\nThe flaw only affects the Red Hat Enterprise Linux 5.4 beta kernel, which includes a backport of the upstream bug fix introducing this flaw (git commit 33dccbb0). This issue did not affect the final released Red Hat Enterprise Linux 5.4 kernel.  It is also possible to mitigate this flaw by ensuring that the permissions for /dev/net/tun is restricted to root only.\n\nThis issue does not affect any other released kernel in any Red Hat product.",
      "lastModified": "2009-09-02T00:00:00",
      "organization": "Red Hat"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}