CVE-2017-1000257
The strlen() is called on a heap based buffer that might not be zero terminated so libcurl might read beyond the end of it into whatever memory lies after (or just crash) and then deliver that to the application as if it was actually downloaded.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (6.22%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An IMAP FETCH response line indicates the size of the returned data, in number of bytes. When that response says the data is zero bytes, libcurl would pass on that (non-existing) data with a pointer and the size (zero) to the deliver-data function. libcurl's deliver-data function treats zero as a magic number and invokes strlen() on the data to figure out the length. The strlen() is called on a heap based buffer that might not be zero terminated so libcurl might read beyond the end of it into whatever memory lies after (or just crash) and then deliver that to the application as if it was actually downloaded.
- CVSS 3.1
- 9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 6.22% probability · 94th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-119
- Affected
- haxx/libcurl · debian/debian linux
- Source
- cve@mitre.org
EPSS 6.2% since 27 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.debian.org/security/2017/dsa-4007Third Party Advisory
- http://www.securityfocus.com/bid/101519Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039644Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2017:3263
- https://access.redhat.com/errata/RHSA-2018:2486
- https://access.redhat.com/errata/RHSA-2018:3558
- https://curl.haxx.se/docs/adv_20171023.htmlVendor Advisory
- https://security.gentoo.org/glsa/201712-04
- http://www.debian.org/security/2017/dsa-4007Third Party Advisory
- http://www.securityfocus.com/bid/101519Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039644Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2017:3263
- https://access.redhat.com/errata/RHSA-2018:2486
- https://access.redhat.com/errata/RHSA-2018:3558
- https://curl.haxx.se/docs/adv_20171023.htmlVendor Advisory
- https://security.gentoo.org/glsa/201712-04
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.