dbcve.org
Ubuntu LinuxOperating system · Canonical

CVE-2015-2806

HIGH · 10.0 CVSS v2.0 Published 2015-04-10
Fix available
A fix is available. Upgrade to after 4.3 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Stack-based buffer overflow in asn1_der_decoding in libtasn1 before 4.4 allows remote attackers to have unspecified impact via unknown vectors.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Stack-based buffer overflow in the asn1_der_decoding function of libtasn1 versions prior to 4.4 allows remote attackers to potentially execute arbitrary code or cause denial of service via specially crafted ASN.1 DER encoded data.

MitigationUpgrade libtasn1 to version 4.4 or later to patch the vulnerability. Identify all applications and systems dependent on the vulnerable library version and update them accordingly.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Ubuntu LinuxOperating system
Affected:= 10.04= 12.04= 14.04= 14.10
Debian LinuxOperating system
Affected:= 7.0
FedoraOperating system
Affected:= 20= 21= 22
Libtasn1Application
Affected:<= 4.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/Au:N/C:C/I:C/A:C

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if libtasn1 is installed
    Run 'dpkg -l | grep libtasn1' on Debian/Ubuntu, 'rpm -qa | grep libtasn1' on Fedora/RHEL, or check for the shared library file 'libtasn1.so' in directories like /usr/lib/
    Affected if libtasn1 package or library file is found on the system
  2. Determine the installed libtasn1 version
    Run 'dpkg -s libtasn1-6' on Debian/Ubuntu, 'rpm -q libtasn1' on Fedora, or use 'objdump -p /usr/lib/libtasn1.so | grep VERSION' to inspect the library version
    Affected if The version number returned is less than 4.4 (for example 4.3, 4.2, 4.1, etc.)
  3. Identify applications linked against libtasn1
    Run 'ldd /usr/bin/* 2>/dev/null | grep libtasn1' or 'ldconfig -p | grep libtasn1' to list programs that link to the library. Common dependents include gnutls, gpg, and certificate-handling tools
    Affected if Any application on the system is dynamically linked to a vulnerable version of libtasn1
  4. Check if affected applications process ASN.1 DER data
    Review logs or documentation for applications that parse certificates, PKI structures, or ASN.1 DER encoded content. Look for use cases involving X.509 certificates, CSR parsing, or cryptographic operations
    Affected if Applications linked to libtasn1 are used to parse or validate ASN.1 DER encoded input from untrusted sources

The system is affected if libtasn1 version 4.3 or earlier is installed AND applications using this library process ASN.1 DER encoded data from potentially untrusted sources.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 4.3
Interim mitigation

Upgrade libtasn1 to version 4.4 or later to patch the vulnerability. Identify all applications and systems dependent on the vulnerable library version and update them accordingly.

Recommended fix High confidence

libtasn1 version 4.4 or later

  1. Check current libtasn1 version installed: dpkg -l | grep libtasn1 (Debian/Ubuntu) or rpm -qa | grep libtasn1 (Fedora)
  2. Update package lists: apt-get update (Debian/Ubuntu) or dnf check-update (Fedora)
  3. Upgrade libtasn1 package: apt-get upgrade libtasn1-6 (Debian/Ubuntu) or dnf update libtasn1 (Fedora)
  4. Verify the installed version is 4.4 or later: dpkg -l | grep libtasn1 or rpm -qa libtasn1
  5. Restart any services that depend on libtasn1 to ensure the updated library is loaded
Caveat Minor - libtasn1 is a low-level library; applications using it should not be affected but may require restart to pick up the new version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Ubuntu Linux Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2015-2806 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data