// For flags

CVE-2016-8622

curl: URL unescape heap overflow via integer truncation

Severity Score

9.8
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

The URL percent-encoding decode function in libcurl before 7.51.0 is called `curl_easy_unescape`. Internally, even if this function would be made to allocate a unscape destination buffer larger than 2GB, it would return that new length in a signed 32 bit integer variable, thus the length would get either just truncated or both truncated and turned negative. That could then lead to libcurl writing outside of its heap based buffer.

La función URL percent-encoding en libcurl en versiones anteriores a la 7.51.0 se denomina "curl_easy_unescape". Internamente, aunque esta función se haya hecho para asignar un búfer de destino no escapado más grande de 2GB, devuelve esa nueva longitud en una variable de enteros de 32 bits. Por lo tanto, la longitud se truncaría o se truncaría y, además, se volvería negativa. Esto podría conducir a que libcurl escriba fuera de su búfer basado en memoria dinámica (heap).

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
Attack Vector
Network
Attack Complexity
High
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2016-10-12 CVE Reserved
  • 2016-11-04 CVE Published
  • 2024-08-06 CVE Updated
  • 2024-11-03 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-122: Heap-based Buffer Overflow
  • CWE-190: Integer Overflow or Wraparound
  • CWE-787: Out-of-bounds Write
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Haxx
Search vendor "Haxx"
 Libcurl
Search vendor "Haxx" for product "Libcurl"
 < 7.51.0
Search vendor "Haxx" for product "Libcurl" and version " < 7.51.0"
-
Affected