CVE-2017-1000254

Impact:
Moderate
Public Date:
2017-10-04
CWE:
CWE-125
Bugzilla:
1495541: CVE-2017-1000254 curl: FTP PWD response parser out of bounds read

The MITRE CVE dictionary describes this issue as:

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.

Find out more about CVE-2017-1000254 from the MITRE CVE dictionary dictionary and NIST NVD.

CVSS v3 metrics

CVSS3 Base Score 3.7
CVSS3 Base Metrics CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity Impact None
Availability Impact Low

Red Hat Security Errata

Platform Errata Release Date
Red Hat JBoss Core Services 1 RHSA-2018:2486 2018-08-16
Red Hat Software Collections for Red Hat Enterprise Linux 6 (httpd24-curl) RHSA-2018:3558 2018-11-13
Red Hat Software Collections for Red Hat Enterprise Linux 7 (httpd24-curl) RHSA-2018:3558 2018-11-13

Affected Packages State

Platform Package State
Red Hat JBoss Web Server 3 curl Not affected
Red Hat Enterprise Linux 7 curl Will not fix
Red Hat Enterprise Linux 6 curl Will not fix
Red Hat Enterprise Linux 5 curl Will not fix
RHEV Manager 3 mingw-virt-viewer Will not fix
.NET Core 2.0 on Red Hat Enterprise Linux rh-dotnet20-curl Will not fix
.NET Core 2.0 on Red Hat Enterprise Linux rh-dotnet21-curl Will not fix
.NET Core 1.0 on Red Hat Enterprise Linux rh-dotnetcore10-curl Will not fix
.NET Core 1.0 on Red Hat Enterprise Linux rh-dotnetcore11-curl Will not fix

Acknowledgements

Red Hat would like to thank the Curl project for reporting this issue. Upstream acknowledges Max Dymond as the original reporter.

External References

Last Modified

CVE description copyright © 2017, The MITRE Corporation

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