CVE-2016-1951
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 · uneditedMultiple integer overflows in io/prprf.c in Mozilla Netscape Portable Runtime (NSPR) before 4.12 allow remote attackers to cause a denial of service (buffer overflow) or possibly have unspecified other impact via a long string to a PR_*printf function.
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 · high confidenceInteger overflows in the PR_*printf functions (prprf.c) within Mozilla Netscape Portable Runtime (NSPR) allow attackers to trigger buffer overflows by providing excessively long strings to formatting functions. This memory corruption can lead to denial of service or potentially arbitrary code execution.
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<= 4.11CVSS 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
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
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 checksWork through these to decide whether this CVE applies to you.
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Locate NSPR library filesSearch for libnspr4.so (Linux) or nspr4.dll (Windows) in system directories such as /usr/lib, /lib, or C:\Windows\System32. Use commands: 'find /usr -name "libnspr*" 2>/dev/null' on Linux or 'dir /s C:\nspr4.dll' on Windows.Affected if NSPR library files are present on the system
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Identify installed NSPR versionRun 'nspr-config --version' if available, or check the library file metadata. On Linux, use 'rpm -q nspr' or 'dpkg -l libnspr4'. On Windows, right-click the DLL and view Properties > Details for the File Version.Affected if The reported version is 4.11 or lower
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Check for applications linking to NSPRIdentify processes or applications that depend on NSPR. On Linux, use 'ldd <executable> | grep nspr' or 'ldconfig -p | grep nspr'. On Windows, use dependency walker tools or check the import tables of binaries in the application directory.Affected if Applications dynamically or statically link to a vulnerable NSPR version <= 4.11
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Audit usage of PR_*printf functionsReview application source code or binary imports for calls to PR_snprintf, PR_vsnprintf, or similar PR_*printf functions. Search for these function calls in application logs or during runtime profiling.Affected if Applications call PR_*printf functions with untrusted, user-controlled string input that could exceed reasonable length limits
The system is affected if NSPR version 4.11 or lower is installed AND applications use the vulnerable PR_*printf functions with potentially long string inputs.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataUpdate NSPR library to version 4.12 or later to obtain the patched integer overflow protections. Recompile any dependent applications that statically link to NSPR.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-1951 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2016-1951 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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