CVE-2018-0688

Open redirect vulnerability in SEIKO EPSON printers and scanners (DS-570W firmware versions released prior to 2018 March 13, DS-780N firmware versions released prior to 2018 March 13, EP-10VA firmware versions released prior to 2017 September 4, EP-30VA firmware versions released prior to 2017 June 19, EP-707A firmware versions released prior to 2017 August 1, EP-708A firmware versions released prior to 2017 August 7, EP-709A firmware versions released prior to 2017 June 12, EP-777A firmware versions released prior to 2017 August 1, EP-807AB/AW/AR firmware versions released prior to 2017 August 1, EP-808AB/AW/AR firmware versions released prior to 2017 August 7, EP-879AB/AW/AR firmware versions released prior to 2017 June 12, EP-907F firmware versions released prior to 2017 August 1, EP-977A3 firmware versions released prior to 2017 August 1, EP-978A3 firmware versions released prior to 2017 August 7, EP-979A3 firmware versions released prior to 2017 June 12, EP-M570T firmware versions released prior to 2017 September 6, EW-M5071FT firmware versions released prior to 2017 November 2, EW-M660FT firmware versions released prior to 2018 April 19, EW-M770T firmware versions released prior to 2017 September 6, PF-70 firmware versions released prior to 2018 April 20, PF-71 firmware versions released prior to 2017 July 18, PF-81 firmware versions released prior to 2017 September 14, PX-048A firmware versions released prior to 2017 July 4, PX-049A firmware versions released prior to 2017 September 11, PX-437A firmware versions released prior to 2017 July 24, PX-M350F firmware versions released prior to 2018 February 23, PX-M5040F firmware versions released prior to 2017 November 20, PX-M5041F firmware versions released prior to 2017 November 20, PX-M650A firmware versions released prior to 2017 October 17, PX-M650F firmware versions released prior to 2017 October 17, PX-M680F firmware versions released prior to 2017 June 29, PX-M7050F firmware versions released prior to 2017 October 13, PX-M7050FP firmware versions released prior to 2017 October 13, PX-M7050FX firmware versions released prior to 2017 November 7, PX-M7070FX firmware versions released prior to 2017 April 27, PX-M740F firmware versions released prior to 2017 December 4, PX-M741F firmware versions released prior to 2017 December 4, PX-M780F firmware versions released prior to 2017 June 29, PX-M781F firmware versions released prior to 2017 June 27, PX-M840F firmware versions released prior to 2017 November 16, PX-M840FX firmware versions released prior to 2017 December 8, PX-M860F firmware versions released prior to 2017 October 25, PX-S05B/W firmware versions released prior to 2018 March 9, PX-S350 firmware versions released prior to 2018 February 23, PX-S5040 firmware versions released prior to 2017 November 20, PX-S7050 firmware versions released prior to 2018 February 21, PX-S7050PS firmware versions released prior to 2018 February 21, PX-S7050X firmware versions released prior to 2017 November 7, PX-S7070X firmware versions released prior to 2017 April 27, PX-S740 firmware versions released prior to 2017 December 3, PX-S840 firmware versions released prior to 2017 November 16, PX-S840X firmware versions released prior to 2017 December 8, PX-S860 firmware versions released prior to 2017 December 7) allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via the web interface of the affected product.

Weakness

A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• Use a list of approved URLs or domains to be used for redirection.
• When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
• For example, ID 1 could map to “/login.asp” and ID 2 could map to “http://www.example.com/". Features such as the ESAPI AccessReferenceMap [REF-45] provide this capability.
• Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
• Many open redirect problems occur because the programmer assumed that certain inputs could not be modified, such as cookies and hidden form fields.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/178.html

References

• https://jvn.jp/en/jp/JVN89767228/index.html
• https://www.epson.jp/support/misc/20181203_oshirase.htm