libcurl may read outside of a heap allocated buffer when doing FTP.
Noroxi assessment
Priority: Monitor (action score 32/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 8.1% (FIRST EPSS); higher than 94.8% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: curl (Alpine:v3.3) 7.55.0-r1; curl (Alpine:v3.5) 7.56.0-r0; curl (Debian:12) 7.56.1-1.
Low priority for now. Upgrade to curl (Alpine:v3.3) 7.55.0-r1; curl (Alpine:v3.5) 7.56.0-r0; curl (Debian:12) 7.56.1-1 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
libcurl may read outside of a heap allocated buffer when doing FTP. When libcurl connects to an FTP server and successfully logs in (anonymous or not), it asks the server for the current directory with the `PWD` command. The server then responds with a 257 response containing the path, inside double quotes. The returned path name is then kept by libcurl for subsequent uses. Due to a flaw in the string parser for this directory name, a directory name passed like this but without a closing double quote would lead to libcurl not adding a trailing NUL byte to the buffer holding the name. When libcurl would then later access the string, it could read beyond the allocated heap buffer and crash or wrongly access data beyond the buffer, thinking it was part of the path. A malicious server could abuse this fact and effectively prevent libcurl-based clients to work with it - the PWD command is always issued on new FTP connections and the mistake has a high chance of causing a segfault. The simple fact that this has issue remained undiscovered for this long could suggest that malformed PWD responses are rare in benign servers. We are not aware of any exploit of this flaw. This bug was introduced in commit [415d2e7cb7](https://github.com/curl/curl/commit/415d2e7cb7), March 2005. In libcurl version 7.56.0, the parser always zero terminates the string but also rejects it if not terminated properly with a final double quote.
- Published
- Oct 6, 2017
- Updated
- Jun 16, 2026
- EPSS
- 8.1% · 94th percentile
- CWE
- CWE-119
Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 2 / 30 · 8.1%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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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.
We use this product, ask for helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| haxx | libcurl | cpe:2.3:a:haxx:libcurl |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- haxx libcurl7.10
- haxx libcurl7.10.1
- haxx libcurl7.10.2
- haxx libcurl7.10.3
- haxx libcurl7.10.4
- haxx libcurl7.10.5
- haxx libcurl7.10.6
- haxx libcurl7.10.7
- haxx libcurl7.10.8
- haxx libcurl7.11.0
- haxx libcurl7.11.1
- haxx libcurl7.11.2
- haxx libcurl7.12.0
- haxx libcurl7.12.1
- haxx libcurl7.12.2
- haxx libcurl7.12.3
- haxx libcurl7.13.0
- haxx libcurl7.13.1
- haxx libcurl7.13.2
- haxx libcurl7.14.0
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.3 | curl | before 7.55.0-r1 | 7.55.0-r1 |
| Alpine:v3.5 | curl | before 7.56.0-r0 | 7.56.0-r0 |
| Debian:12 | curl | before 7.56.1-1 | 7.56.1-1 |
| Debian:7 | curl | before 7.26.0-1+wheezy21 | 7.26.0-1+wheezy21 |
| Debian:8 | curl | before 7.38.0-4+deb8u6 | 7.38.0-4+deb8u6 |
| Debian:9 | curl | before 7.52.1-5+deb9u1 | 7.52.1-5+deb9u1 |
| openSUSE:Tumbleweed | curl | before 7.79.1-1.1 | 7.79.1-1.1 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-curl | before 0:7.61.1-1.el6 | 0:7.61.1-1.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-curl-debuginfo | before 0:7.61.1-1.el6 | 0:7.61.1-1.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-httpd | before 0:2.4.34-7.el6 | 0:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-httpd-debuginfo | before 0:2.4.34-7.el6 | 0:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-httpd-devel | before 0:2.4.34-7.el6 | 0:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-httpd-manual | before 0:2.4.34-7.el6 | 0:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-httpd-tools | before 0:2.4.34-7.el6 | 0:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-libcurl | before 0:7.61.1-1.el6 | 0:7.61.1-1.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-libcurl-devel | before 0:7.61.1-1.el6 | 0:7.61.1-1.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-libnghttp2 | before 0:1.7.1-7.el6 | 0:1.7.1-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-libnghttp2-devel | before 0:1.7.1-7.el6 | 0:1.7.1-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-mod_ldap | before 0:2.4.34-7.el6 | 0:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-mod_proxy_html | before 1:2.4.34-7.el6 | 1:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-mod_session | before 0:2.4.34-7.el6 | 0:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-mod_ssl | before 1:2.4.34-7.el6 | 1:2.4.34-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-nghttp2 | before 0:1.7.1-7.el6 | 0:1.7.1-7.el6 |
| Red Hat:rhel_software_collections:3::el6 | httpd24-nghttp2-debuginfo | before 0:1.7.1-7.el6 | 0:1.7.1-7.el6 |
+23
Same product
haxx: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-38545This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy
handshake.63This week
- CVE-2019-5436A heap buffer overflow in the TFTP receiving code allows for DoS or arbitrary code execution in libcurl versions 7.19.4 through 7.64.1.46Plan
- CVE-2019-3822libcurl versions from 7.36.0 to before 7.64.0 are vulnerable to a stack-based buffer overflow.43Plan
Published before and after this one in the same product
- ← EarlierCVE-2017-1000099Oct 4, 2017 · When asking to get a file from a file:// URL, libcurl provides a feature that outputs meta-data about the file using HTTP-like headers.27Monitor
- ← EarlierCVE-2017-1000100Oct 4, 2017 · When doing a TFTP transfer and curl/libcurl is given a URL that contains a very long file name (longer than about 515 bytes), the file name 27Monitor
- Later →CVE-2017-1000257Oct 31, 2017 · An IMAP FETCH response line indicates the size of the returned data, in number of bytes.38Monitor
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 |
|---|---|---|
| alpine:curl | 7.55.0-r1 · Alpine:v3.3 | Package registry (OSV) |
| debian:curl | 7.56.1-1 · Debian:12 | Package registry (OSV) |
| opensuse:curl | 7.79.1-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:httpd24-curl | 0:7.61.1-1.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-curl-debuginfo | 0:7.61.1-1.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-httpd | 0:2.4.34-7.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-httpd-debuginfo | 0:2.4.34-7.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-httpd-devel | 0:2.4.34-7.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-httpd-manual | 0:2.4.34-7.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-httpd-tools | 0:2.4.34-7.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-libcurl | 0:7.61.1-1.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-libcurl-devel | 0:7.61.1-1.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-libnghttp2 | 0:1.7.1-7.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-libnghttp2-devel | 0:1.7.1-7.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:httpd24-mod_ldap | 0:2.4.34-7.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| suse:curl | 7.19.7-1.20.53.6.1 · SUSE:Studio Onsite 1.3 | Package registry (OSV) |
| suse:curl-openssl1 | 7.19.7-1.70.8.1 · SUSE:Linux Enterprise Server 11-SECURITY | 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.
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
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (10 more)Show less
- www.securityfocus.com/bid/101115
- www.securitytracker.com/id/1039509
- access.redhat.com/errata/RHSA-2018:2486
- access.redhat.com/errata/RHSA-2018:3558
- curl.haxx.se/673d0cd8.patch
- curl.haxx.se/docs/adv_20171004.html
- lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
- lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
- security.gentoo.org/glsa/201712-04
- support.apple.com/HT208331
Vendor advisories and official records. Exploit/PoC links are deliberately left out.