The ADDW macro in stdio-common/vfscanf.c in the GNU C Library (aka glibc or libc6) before 2.21 does not properly consider data-type size dur
The ADDW macro in stdio-common/vfscanf.c in the GNU C Library (aka glibc or libc6) before 2.21 does not properly consider data-type size during a risk-management decision for use of the alloca function, which might allow context-dependent attackers to cause a denial of service (segmentation violation) or overwrite memory locations beyond the stack boundary via a long line containing wide characters that are improperly handled in a wscanf call.
- Published
- Apr 8, 2015
- Updated
- Jun 16, 2026
- EPSS
- 2.1% · 81th percentile
- CWE
- CWE-119
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Report tools
Action score
26
Monitor
Low priority for now.
- CVSS
- 25 / 40 · 6.4 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.1%
Affected systems
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- canonical ubuntu linux10.04
- canonical ubuntu linux12.04
- canonical ubuntu linux14.04
- canonical ubuntu linux14.10
- gnu glibcup to 2.20 inclusive
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | glibc | before 2.19-15 | 2.19-15 |
| Debian:6.0 | eglibc | before 2.11.3-4+deb6u5 | 2.11.3-4+deb6u5 |
| Debian:7 | eglibc | before 2.13-38+deb7u8 | 2.13-38+deb7u8 |
| openSUSE:Tumbleweed | glibc | before 2.24-2.3 | 2.24-2.3 |
| Red Hat:enterprise_linux:7::client | glibc | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:enterprise_linux:7::client | glibc-common | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:enterprise_linux:7::client | glibc-debuginfo | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:enterprise_linux:7::client | glibc-debuginfo-common | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:enterprise_linux:7::client | glibc-devel | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:enterprise_linux:7::client | glibc-headers | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:enterprise_linux:7::client | glibc-static | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:enterprise_linux:7::client | glibc-utils | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:enterprise_linux:7::client | nscd | before 0:2.17-105.el7 | 0:2.17-105.el7 |
| Red Hat:rhel_eus:7.1::computenode | glibc | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::computenode | glibc-common | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::computenode | glibc-debuginfo | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::computenode | glibc-debuginfo-common | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::computenode | glibc-devel | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::computenode | glibc-headers | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::computenode | glibc-static | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::computenode | glibc-utils | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::computenode | nscd | before 0:2.17-79.el7_1 | 0:2.17-79.el7_1 |
| Red Hat:rhel_eus:7.1::server | glibc | before 0:2.17-79.ael7b_1 | 0:2.17-79.ael7b_1 |
| Red Hat:rhel_eus:7.1::server | glibc-common | before 0:2.17-79.ael7b_1 | 0:2.17-79.ael7b_1 |
+7
Same product
gnu: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-4911Glibc: buffer overflow in ld.so leading to privilege escalationKEV85Now
- CVE-2015-0235Heap-based buffer overflow in the __nss_hostname_digits_dots function in glibc 2.2, and other 2.x versions before 2.18, allows context-depen68This week
- CVE-2015-7547Multiple stack-based buffer overflows in the (1) send_dg and (2) send_vc functions in the libresolv library in the GNU C Library (aka glibc 59Plan
- CVE-2024-2961The iconv() function in the GNU C Library versions 2.39 and older may overflow the output buffer passed to it by up to 4 bytes when converti55Plan
- CVE-2018-11236stdlib/canonicalize.c in the GNU C Library (aka glibc or libc6) 2.27 and earlier, when processing very long pathname arguments to the realpa41Plan
- CVE-2015-8779Stack-based buffer overflow in the catopen function in the GNU C Library (aka glibc or libc6) before 2.23 allows context-dependent attackers41Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:eglibc | 2.11.3-4+deb6u5 · Debian:6.0 | Package registry (OSV) |
| debian:glibc | 2.19-15 · Debian:12 | Package registry (OSV) |
| opensuse:glibc | 2.24-2.3 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:glibc | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:glibc-common | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:glibc-debuginfo | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:glibc-debuginfo-common | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:glibc-devel | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:glibc-headers | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:glibc-static | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:glibc-utils | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:nscd | 0:2.17-105.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- P · data or configuration can be modified
- Availability
- P · the service can be disrupted
- Attack complexity
- Low
- Confidentiality impact
- None
- Integrity impact
- P
- Availability impact
- P
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
AV:N/AC:L/Au:N/C:N/I:P/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.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Buffer ManipulationCAPEC-123likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- openwall.com/lists/oss-security/2015/02/04/1
- www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
- www.securityfocus.com/bid/72499
- www.ubuntu.com/usn/USN-2519-1
- sourceware.org/git/gitweb.cgi?p=glibc.git%3Ba=commit%3Bh=5bd80bfe9ca0d955bfbbc002781bc7b01b6bcb06
Vendor advisories and official records. Exploit/PoC links are deliberately left out.